• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.590-596
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• 2020

The fabric used for military winter inner clothing(top) is quilted with padded cotton to provide warmth. This quilting fabric is generally manufactured with yarns that intersect and are sewn substantially between the fabric and cotton. Thus, it is impossible to separate the fabric and cotton once after the quilting fabric is manufactured, which can result in a significant loss of fabric and cotton when separated. In this study, after fabricating the quilting fabric, we investigated a method to stabilize change rate of thickness and increase the warmth keeping property through subsequent processing without damaging the fabric. A relatively method of passing the quilting fabric through a part of the cotton production facility was used generally, and the following results were obtained. This indicates that after the quilting fabric was manufactured, the warmth keeping property was improved through the subsequent processing steps, so that the change rate of thickness due to washing was stabilized.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.176-183
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• 2020

A ship has three types of diving systems (Diver Stage Diving, Wet Bell Diving and Scuba Diving) to carry out a search-and-rescue operation. To reduce the possibility of decompression sickness, any diving systems shall comply with the decompression procedure according to the decompression table corresponding to the diving depth and diving time. The decompression procedure is largely divided into two methods: underwater decompression and underwater-onboard decompression. In particular, the surface interval shall not exceed 5 minutes, which is the phase from underwater decompression to underwater-onboard decompression, in accordance with the U.S Navy Diving Manual. However, the surface interval is greater than 5 minutes as a result of using Wet Bell Diving. This paper describes the result of cause analysis and measurement with improved Wet Bell Diving. Using improved Wet Bell Diving reduced the surface interval to less than 5 minutes. The result of the research can be used for operation and improving the performance of diving systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.508-515
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• 2020

This study examined the research trends of "Microplastic in food" with a scholar databaseusing the centrality analysis method. The data was based on research papers published from 2011 to 2020, sorted by "microplastic" and "food". The centrality analysis methodology(Degree centrality, Closeness centrality, Betweenness centrality) was applied, followed by a keyword-based frequency occurrence analysis. The results suggested that more than 30% of the total keywords were related to "marine" and "pollution". Therefore, research on the effects of microplastic pollution on the ecosystem had mainly been conducted. On the other hand, only 6% of the keywords were related to "toxicity" and "ingestion". Hence,the number of studies on microplastic exposure caused by bioaccumulation or food are still insufficient. These results can be used to provide directions for future research, as well as provide basic data for political decision-making on the environmental hazards of microplastic.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.623-629
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• 2020

This study examined the airflow field around a gun port on the flight condition of gunfire to verify the aircraft performance and safety effects and gun gas rate, path according to the options of diverter configuration. The gun port diverter not only effectively lowered the heat generated by gunfire but also effectively discharged the gun gas upwards. The path of gun gas can be changed according to its configuration. According to the optional configuration of the rear-gun-port diverter, the flow rate, path, and pressure of the gun gas were analyzed during gunfire. An analysis of the internal velocity distribution and the temperature change of the gun port revealed a rapid decrease in flow rate through the rear diverter according to the option configuration. The forward flow rate showed a similar tendency with little change. This ensures that the gun gas generated during gunfire has a sufficient flow distance from the aircraft surface, regardless of the rear gun port diverter's optional configuration. The flow stagnation of gun gas according to the option configuration of diverter had a great influence on the internal temperature rise of a gun port.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.337-343
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• 2020

This study proposed piezoelectric ceramic bender actuators for application to small walking robots. As the space where human access has recently become increasingly restricted (e.g., highly concentrated radioactive storage areas, viral contaminated areas, terrorist zones, etc.), the scope of using robots is becoming more diverse, and many actions that were possible only in the past have been attempted to be replaced by small robots. This robotic concept has the advantage of being simple in structure, making it compact and producing a large size work force. The dynamic modeling, using finite element analysis, maximized the robot's mobility performance by optimizing the shape of the actuator, and the results were verified through fabrication and experimentation. The actuator moved at a maximum speed of 236 mm/s under no load conditions, and it could move at a speed of 156 mm/s under load conditions of 5g. The proposed actuator has the advantage of modular additions depending on the mission and required performance, which ensured that they are competitive against similar drive sources previously created.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.689-695
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• 2018

This paper presents the means of controlling the regeneration of a diesel particulate filter (DPF) that is mounted on tactical vehicles to satisfy exhaust gas standards. The DPF captures particulate matter in the exhaust gas and combusts the captured particulate matter. This process is regeneration, which is essential to the normal performance of the DPF. Bad regeneration causes degradation of vehicle performance; worse, it can lead to a vehicle fire. DPF regeneration is performed by control logic. If the regeneration control logic does not properly reflect the operating characteristics of the vehicle, DPF regeneration may not occur. Consequently, it is very important to ensure the DPF operates properly by reflecting the operating characteristics of the tactical vehicle. This study analyzes the operational characteristics of a tactical vehicle and the DPF, and adds proper DPF regeneration control logic. Additionally, this study is intended to simultaneously improve the additional problems that may occur from operating under the added regeneration control logic.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3633-3642
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• 2015

Single-base propellants contain a single energetic component: nitrocellulose. Accurate predictions of propellant shelf-life should result in cost savings in terms of human and material resources. This study derived an optimized kinetic model reaction order that described stabilizer consumption and estimated propellant shelf-life. High temperature accelerated aging tests gave an optimum reaction order value of 1.15481, from which the minimum standard error of a linear regression estimate of 16.284 was obtained. At normal storage temperature of $21-30^{\circ}C$, propellants should have a safe shelf-life of 140 years, and a minimum of 35 years. It is necessary to consider the temperature range in ammunition storage areas to predict propellant shelf-life more accurately.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.174-180
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• 2019

In this study, we evaluated and analyzed the properties of polymeric transparent films used in military vehicle covers according to weathering test. Two types of polymer films (Film A and Film B) that are mostly used for military vehicle covers were selected. The weathering treatment condition and tester are described in KS K 0706, and the following weathering times were tested: 0hour, 40hours, 160hours and 320 hours. The tensile strength, elongation and thermal decomposition behavior and optical characteristics were analyzed. The tensile strength tended to decrease - increase - decrease with increasing weathering treatment time in both transparent films. The thermal decomposition temperature gradually decreased. Regarding the optical property, the light transmittance decreased and the haze tended to increase. However, film A showed almost similar optical characteristics after 160-hour weathering treatment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.485-491
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• 2019

In this paper, we present a process and case of RAM analysis using Field-Data of the ground weapon system in operation in the army. In order to perform RAM analysis in filed-Data, we propose data collection, data refining and calibration, and RAM analysis process. RAM analysis was performed with the RAM verification and evaluation system developed by Defense Agency for Technology and Quality. We enhance the objectivity and reliability in result of data, which contains a variety of conditions; operation and maintenance concept of domestic ground weapon system, relevant regulation and after-sales service data of developer. Results are compared 2015, 2018 and development RAM value. We prove results of RAM analysis through discussion experts. Studies show that proposed method can effectively apply database from setting to evaluation RAM value in various ground weapon system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.492-501
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• 2019

To use the system safely in cyberspace, you need to use a security solution that is appropriate for your situation. In order to strengthen cyber security, it is necessary to accurately understand the flow of security from past to present and to prepare for various future threats. In this study, information security words of security/hacking news of Naver News which is reliable by using text mining were collected and analyzed. First, we checked the number of security news articles for the past seven years and analyzed the trends. Second, after confirming the security/hacking word rankings, we identified major concerns each year. Third, we analyzed the word of each security solution to see which security group is interested. Fourth, after separating the title and the body of the security news, security related words were extracted and analyzed. The fifth confirms trends and trends by detailed security solutions. Lastly, annual revenue and security word frequencies were analyzed. Through this big data news analysis, we will conduct an overall awareness survey on security solutions and analyze many unstructured data to analyze current market trends and provide information that can predict the future.