• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.451-458
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• 2019

Reliability in the course of weapons system development and operation is a key measure of the ability of a system to perform the required functions under specified conditions over a specified period of time, and the mission confidence for the assessment of mission fulfillment is an important indicator of victory or defeat in a battle. Mission reliability indicates the probability that a given task will succeed or fail in an event or environmental situation over a given period of time. The existing mission reliability was calculated after creating a confidence blow map with only physical connections based on the mission. However, as modern weapons systems evolve and advance, the related equipment structure becomes increasingly complex, making it impossible to express mission relevance when mission classification is required based on functional or physical connections. In this study, the mission reliability was calculated for a gun control system, which is part of a ship's combat system, by expressing the association between the physical and functional structures using the design structure matrix technique and the interface matrix technique. We expect the study results to be used as verification data for mission reliability.

• Composites Research
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• v.32 no.5
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• pp.229-236
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• 2019

In this study, the effects of the additional processing parameters on the mechanical properties of thermoplastic composites fabricated with automated fiber placement (AFP) were evaluated. Annealing and vacuum bag only processes were then performed on the manufactured thermoplastic composites, respectively. For verification, the crystallinity was measured by differential scanning calorimetry (DSC), confirming the variation of semi-crystalline thermoplastic composite according to the process conditions. The void content of thermoplastic composites was evaluated by matrix digestion method while microscopic examination confirmed the porosity distribution. The interlaminar shear strength test was conducted for three different process parameters (VBO, annealing, and no treatment). A comparison of the three tested strengths was made, revealing that the porosity value had larger effect on the mechanical properties of the thermoplastic composite compared to the degree of crystallinity. Additionally, when thermoplastic composite melted up, the pores were continuously removed under vacuum process; the removal of the pores resulted in an increase of the interlaminar shear strength.

• Korean Journal of Community Nutrition
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• v.24 no.1
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• pp.60-76
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• 2019

Objectives: The purpose of this study was to develop a systematic and standardized "The Survey on School Foodservice Program" that can identify the current status of school meals on the nationwide level. Methods: This study was carried out in six steps of the analysis of report/investigation data related to school foodservice in metropolitan and provincial offices of education, analysis of preceding research related to the actual status of school foodservice, field verification of the actual condition of the school foodservice site, development of a draft of "The Survey on School Foodservice Program", pilot study of a draft of "The Survey on School Foodservice Program", and suggestions of a final model of "The Survey on School Foodservice Program" from August to December, 2017. Statistical analysis was performed for frequency analysis and descriptive analysis using the SPSS program ver. 23. Results: A draft of "The Survey on School Foodservice Program" was developed by analyzing the current status of report/research data on school meals in metropolitan and provincial offices of education, analyzing the preceding research on school meals, and identifying the actual conditions at school foodservice sites. To verify the validity of the school foodservice survey questionnaire, 1,031 schools were sampled from a total of 10,251 schools and the pilot test of '2017 School Foodservice Survey' was conducted. The final model of "The Survey on School Foodservice Program" consisted of 12 survey sections, 29 survey categories, and 433 survey items, and the survey cycle was set for one year and three years for each survey item. Conclusions: Based on the objective statistical data through "The Survey on School Foodservice Program", it is possible to develop the school foodservice policy, which will help establish the reliability of the school meals.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.21-28
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• 2021

The main purpose of this study is to assess the safety of the fixed anchorages subjected to the seismic motion for an operating facilities in the actual power plant. Thus, the experimental study was conducted to investigate the load response in the event of an actual seismic to the anchorages of a nonstructural components. Since there are economic and spatial constraints to study nonstructural components that actually have various forms, alternative test specimens of steel frames with mass were built and the shaking table test was carried out. In order to evaluate the dynamic characteristics and seismic performance, the natural frequency of the target structure was identified through the shaking table test and then the load response characteristics of the anchorage were evaluated by generating an artificial seismic effect like actual seismic. Finally, the structural stiffness was reinforced by fixing the steel frame to the test specimen using bolts, thereby reducing the load transmitted to the anchorage. It will be carried out on the reliability verification of the experiments and areas that have not been carried out due to the site conditions through the analytical approach in the future.

• Journal of Environmental Impact Assessment
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• v.29 no.6
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• pp.403-413
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• 2020

A mathematical model comprised with eight simultaneous quasi-linear partial differential equations was suggested to provide optimal chlorination strategy. Upstream weighted finite element method was employed to construct multidimensional numerical code. The code was verified against measured concentrations in three type of reactors. Boundary conditions and reaction rate were calibrated for the sixteen cases of experimental results to regenerate the measured values. Eight reaction rate coefficients were estimated from the modeling result. The reaction rate coefficients were expressed in terms of pH and temperature. Automatic optimal algorithm was invented to estimate the reaction rate coefficients by minimizing the sum of squares of the numerical errors and combined with the model. In order to minimize the concentration of chlorine and pollutants at the final usage sites, a real-time predictive control system is imperative which can predict the water quality variables from the chlorine disinfection process at the water purification plant to the customer by means of a model and operate the disinfection process according to the influent water quality. This model can be used to build such a system in water treatment plants.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.222-234
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• 2020

Autonomous vehicles are equipped with a wide rage of sensors such as GPS, RADAR, LIDAR, camera, IMU, etc. and are driven by recognizing and judging various transportation systems at intersections in the city. The accident ratio of the intersection of the autonomous vehicles is 88% of all accidents due to the limitation of prediction and judgment of an area outside the sensing distance. Not only research on non-signalized intersection collision avoidance strategies through V2V and V2I is underway, but also research on safe intersection driving in failure situations is underway, but verification and fragments through simple intersection scenarios Only typical V2V failures are presented. In this paper, we analyzed the architecture of the V2V module, analyzed the causal factors for each V2V module, and defined the failure mode. We presented intersection scenarios for various road conditions and traffic volumes. we used the ISO-26262 Part3 Process and performed HARA (Hazard Analysis and Risk Assessment) to analyze the risk of autonomous vehicle based on the simulation. We presented ASIL, which is the result of risk analysis, proposed a monitoring concept for each component of the V2V module, and presented monitoring coverage.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.969-976
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• 2020

Urban Air Mobility is attracting attention as a future innovation industry around the world, and leading industries are considering the application of composite materials for structural robustness and lightening in the designing and manufacturing new concept eVTOL aircraft. To apply composite materials to the new concept of eVTO aircraft, this paper was analyzed about composite material qualification system of FAA & EASA and institutionalized by Korea Government, including the procedures and methods, the organization to carry out the material verification for domestic conditions. The domestic composite material qualification system will not only make it easier for manufacturers of eVTOL aircraft with a new concept to apply composite materials to domestic aircraft through pre-material qualification, but also reduce the burden of material qualification within the period of type certification. In addition, domestic manufacturers of composite materials with qualified material quality and performance will be easy to enter for domestic aircraft applications and composite material manufacturers with experience in applying to aircraft will have a positive impact on overseas exports. This system will be able to promote the development eVTOL aircraft industry of a new concept and enhance international credibility of made aircraft in Korea.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.3
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• pp.217-226
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• 2022

In the view of the application of high-precision spatial information production, UAV (Umanned Aerial Vehicle)-Photogrammetry has a problem in that it lacks specific procedures and detailed regulations for quantitative quality verification methods or certification of captured images. In addition, test tools for UAV image quality assessment use only the GSD (Ground Sample Distance), not MTF (Modulation Transfer Function), which reflects image resolution and contrast at the same time. This fact makes often the quality of UAV image inferior to that of manned aerial image. We performed MTF and GSD analysis simultaneously using a siemens star to confirm the necessity of MTF analysis in UAV image quality assessment. The analyzing results of UAV images taken with different payload and sensors show that there is a big difference in σ_MTF values, representing image resolution and the degree of contrast, but slightly different in GSD. It concluded that the MTF analysis is a more objective and reliable analysis method than just the GSD analysis method, and high-quality drone images can only be obtained when the operator make images after judging the proper selection the sensor performance, image overlaps, and payload type. However, the results of this study are derived from analyzing only images acquired by limited sensors and imaging conditions. It is therefore expected that more objective and reliable results will be obtained if continuous research is conducted by accumulating various experimental data in related fields in the future.

• Journal of Environmental Impact Assessment
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• v.31 no.3
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• pp.129-140
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• 2022

Environmental impact assessment on development projects is a process in which various stakeholders derive consultations by reflecting project characteristics and regional environmental status, and implementation of consultations is a prerequisite for securing sustainability of the local environment. The business plan can be changed to respond to changes in social and environmental conditions. And the business plan for which the environmental impact assessment consultation has been completed, it can be changed as a systematically prepared procedure (called Consultations on Amendment). As a result of investigating and analyzing the current status and major changes in the development project, Consultations on Amendment in industrial complexes were the most common, and the environmental impact is increasing accordingly. As the results of the analysis of operational status and the case studies, the main causes of Consultations on Amendment in industrial complex can be summarized into three categories: (1) formal demand forecasting for tenant industries, (2) excessive omission and simplification of administrative procedures under the Special Act, and (3) the use of an expedient change consultation system to facilitate environmental impact assessment consultation and shorten the period. This study proposes the following three measures to prevent the deterioration of the environmental impact assessment function due to frequent consultations on industrial complex changes; (1) Ensuring residents' participation procedures for Consultations on Amendment that changes important matters, (2) Reasonable revision of the "Simplification of Industrial Complex Procedures Act" to enhance the feasibility of industrial complex development plans and locations, (3) Development of evaluation criteria and methods for verification of real demand for objective demand management for industrial complexes, and (4) Preparation of a review guideline for Consultations on Amendment.

• Advances in nano research
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• v.12 no.5
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• pp.501-514
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• 2022

This study aimed to investigate the effects and potential mechanisms of Chikusetsusaponin V (CsV) on endothelial nitric oxide synthase (eNOS) and vascular endothelial cell functions. Different concentrations of CsV were added to animal models, bovine aorta endothelial cells (BAECs) and human umbilical vein endothelial cells (HUVECs) cultured in vitro. qPCR, Western blotting (WB), and B ultrasound were performed to explore the effects of CsV on mouse endothelial cell functions, vascular stiffness and cellular eNOS mRNA, protein expression and NO release. Bioinformatics analysis, network pharmacology, molecular docking and protein mass spectrometry analysis were conducted to jointly predict the upstream transcription factors of eNOS. Furthermore, pulldown and ChIP and dual luciferase assays were employed for subsequent verification. At the presence or absence of CsV stimulation, either overexpression or knockdown of purine rich element binding protein A (PURA) was conducted, and PCR assay was employed to detect PURA and eNOS mRNA expressions, Western blot was used to detect PURA and eNOS protein expressions, cell NO release and serum NO levels. Tube formation experiment was conducted to detect the tube forming capability of HUVECs cells. The animal vasodilation function test detected the vasodilation functions. Ultrasonic detection was performed to determine the mouse aortic arch pulse wave velocity to identify aortic stiffness. CsV stimulus on bovine aortic cells revealed that CsV could upregulate eNOS protein levels in vascular endothelial cells in a concentration and time dependent manner. The expression levels of eNOS mRNA and phosphorylation sites Ser1177, Ser633 and Thr495 increased significantly after CsV stimulation. Meanwhile, CsV could also enhance the tube forming capability of HUVECs cells. Following the mice were gavaged using CsV, the eNOS protein level of mouse aortic endothelial cells was upregulated in a concentration- and time-dependent manner, and serum NO release and vasodilation ability were simultaneously elevated whereas arterial stiffness was alleviated. The pulldown, ChIP and dual luciferase assays demonstrated that PURA could bind to the eNOS promoter and facilitate the transcription of eNOS. Under the conditions of presence or absence of CsV stimulation, overexpression or knockdown of PURA indicated that the effect of CsV on vascular endothelial function and eNOS was weakened following PURA gene silence, whereas overexpression of PURA gene could enhance the effect of CsV upregulating eNOS expression. CsV could promote NO release from endothelial cells by upregulating the expression of PURA/eNOS pathway, improve endothelial cell functions, enhance vasodilation capability, and alleviate vessel stiffness. The present study plays a role in offering a theoretical basis for the development and application of CsV in vascular function improvement, and it also provides a more comprehensive understanding of the pharmacodynamics of CsV.