• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.68-73
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• 2020

The proportion of airline accidents caused by human factors is steadily increasing. The aviation industry has made considerable progress in reducing the accident rate; however, since the early 1980s, the accident rate has remained constant. Due to airspace congestion, the safety margins of these existing safety promotion methods are gradually decreasing; thus, new methods to prevent accidents and quasi-accidents must be devised. Causative factors of aviation accidents include increased air traffic due to increased air demand, increased cumulative working hours due to long-distance flights, and complicated flight environments. Accidents often occur when several small errors accumulate in the normal course of operation, rather than after a single error. Accordingly, in this study, the impacts on air navigation due to human error by aviation maintenance personnel and varying international standards (i.e., KOCA vs. F.A.A vs. EASA) analyzed, and the relationship between human decision-making and behavior was investigated. The resulting safety analysis and alternatives were presented to prevent aviation maintenance accidents and cognitive ergonomics errors.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.4
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• pp.116-125
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• 2023

Gimpo International Airport is a strategically utilized airport based on government policy, but there are many residents living around the airport, so it is very sensitive to changes in airport operation. In the past, similar noise results were obtained for aircraft noise at Gimpo International Airport despite changes in aircraft types and an increase in the number of aircraft operating, and recently ICAO proposed a low-noise aircraft noise standard (Ch.14). Since the new standard has a noise reduction effect of up to 15dB compared to existing aircraft noise, ICAO and Europe EASA predict that future aircraft noise will be reduced if the latest technologies such as low-noise aircraft are applied. Therefore, this study establishes the aircraft operation performance and measured noise of Gimpo International Airport in 2022 as a baseline scenario, noise changes using various scenarios of introduction of low-noise aircraft, operation of mid-to-long-distance routes, and changes in future air traffic demand were analyzed using simulation.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.1
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• pp.39-48
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• 2024

Aviation industry is moving towards the third innovative era of AAM with electric power and AI after the JET-powered era following the Wright brothers' first flights. Research on UAM, eVTOL development, certification, and operations is competitively progressing, primarily in aviation-leading countries, aiming to resolve urban traffic saturation and foster the future aviation industries. This study introduces the concept of the pilot's role transition in operational safety as AI autonomous flight advances, comparing K-UAM operational concept with research from FAA, NASA, and EASA. It is to identify and propose solutions for challenges from the pilot's perspective in developing UAM and its safe operation system. To succeed in Advanced Air Mobility National Project, we suggest the collaboration among industry, academia, and institutions, along with the cooperation between civilians, governments, military, and the need for Urban Air Mobility integrated policies.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.1
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• pp.79-90
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• 2024

UAM is emerging due to the deepening population concentration in the metropolitan area and the problem of congested ground transportation in urban areas. Accordingly, along with research on eVTOL aircraft for UAM services, interest in vertiport, the interest in vertiports, the infrastructure that allows eVTOLs to take off and land, is also increasing. However, behind the concentration of population in the metropolitan area, aphenomenon of local extinction is occurring in conjunction with the aging population. AAM, which moves quickly through 3D space, can be an effective SOC facility in times of local extinction crisis. In this paper, we introduce a design plan from the perspective of a complex transper center for a regional hub-level vertiport that can connect with local high-speed rail and utilize local airports in compliance with the vertiport design guidelines issued by FAA(Federal Aviation Administration) and EASA(European union Aviation Safety Agency). We would like to present Vertiport's future operation plan.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7835-7838
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• 2014

Background: Neuroendocrine tumors have widespread and different clinical presentations and prognoses. This study was conducted to assess their survival time and prognostic factors in Iran. Materials and Methods: In a retrospective cohort study, 189 patients diagnosed of having neuroendocrine carcinoma were chosen. The tumor and clinical characteristics of the patients were modeled with a Cox proportional hazard approach. Survival was assessed using Kaplan-Meyer curves. Results: Crude median survival time was 30 months. Women survived longer than men (the median survival time for women was 40 and for men was 24 months). Age (<60 vs >60 years old with hazard ratio (HR) of 2.43, 95% CI 1.3-4.5), primary pathology report (carcinoid vs. others with HR 5.85 cm, 95% CI 2.4-14.3), tumor size cm (for 5-10, HR of 3.1, 95% CI 1.6 and for >10 HR of 8.2, 95% with 95% CI 3.1-21.9), and chemotherapy with single drug (taking vs. not taking with a HR 2.2, 95% CI 1.1-4.8) had significant effects on overall survival of patients. Conclusions: Survival time in patients with neuroendocrine carcinomas is related to demographics, clinical characteristics, tumor histology, and subtype specific treatment.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.4
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• pp.119-125
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• 2013

Since year 2001 to the present time, the aircraft accidents and serious incidents in our country have surpassed 150 occurrences. The Boeing has published the statistical summary of commercial jet airplane accidents annually for the past 10 years on the basis of the occurrence categories defined by the CICTT(CAST/ICAO Common Taxonomy Team), and the number of occurrences is in order of loss of control(LOC-I), controlled flight into terrain(CFIT) and runway excursion (RE). Like the NTSB and the EASA, when fatal and non-fatal accidents are aggregated, though fatality rate is low, abnormal runway contact(ARC), system/component failure(SCF-PP/NP), ground handling(RAMP) rank high in the CICTT occurrence categories. With the less occurrence frequency, it is difficult to statistically analyze the aircraft accidents in our country, thus customarily the accidents and the serious incidents on aggregate are consolidated, and the statistical analysis is performed. This study categorizes the accidents and serious incidents to the domestic transportation aircraft in the past 10 years according to the CICTT occurrence categories, that is compared with foreign practices, and the implications have been discussed. From years 2001 through 2010, the accidents to the domestic transportation aircraft occurred in order of system failure(SCF-NP), ARC and power plant failure(SCF-PP), and when the accidents and the serious incidents are consolidated and analyzed, it is verified that a distribution appears similar to the European accident occurrence categories defined from 300 accident occurrence data.

• Advances in aircraft and spacecraft science
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• v.1 no.2
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• pp.233-251
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• 2014

Each aircraft have to be certified for a specified level of impact energy, for assuring the capability of a safe flight and landing after the impact against a bird at cruise speed. The aim of this research work was to define a scientific and methodological approach to the study of the birdstrike phenomenon against several windshield geometries. A series of numerical simulations have been performed using the explicit finite element solver code LS-Dyna, in order to estimate the windshield-surround structure capability to absorb the bird impact energy, safely and efficiently, according to EASA Certification Specifications 25.631 (2011). The research considers the results obtained about a parametric numerical analysis of a simplified, but realistic, square flat windshield model, as reported in the last work (Grimaldi et al. 2013), where this model was subjected to the impact of a 1.8 kg bird model at 155 m/s to estimate the sensitivity of the target geometry, the impact angle, and the plate curvature on the impact response of the windshield structure. Then on the basis of these results in this paper the topic is focused about the development of a numerical simulation on a complete aircraft windshield-surround model with an innovative configuration. Both simulations have used a FE-SPH coupled approach for the fluid-structure interaction. The main achievement of this research has been the collection of analysis and results obtained on both simplified realistic and complete model analysis, addressed to approach with gained confidence the birdstrike problem. Guidelines for setting up a certification test, together with a design proposal for a test article are an important result of such simulations.

• Transactions of the KSME C: Technology and Education
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• v.3 no.1
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• pp.71-78
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• 2015

Although there are differences in the classification of category adopted by each country, small UAS is usually classified as the one less than 25 kg. UAS has been mainly used for military and public purposes, but in recent years, it has spread to the private sector for hobby, media, and so on. Especially, considering the nature of the operating region and applications, it is necessary to improve operating time, noise and vibration in small UAS to ensure the same level of safety with a manned aircraft. This is because the drone can pose health and safety hazard through collision with manned aircraft or crashing into the ground. In this paper, we investigated operational regulations in the United States and European countries. Based on the investigation, a domestic system development plan for small UAS operation is under development.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.7-14
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• 2022

This study aimed to test the factor structure of the measure of student participation in distance education. The study population consisted of all teachers in public education and faculty members in higher education in the Kingdom of Saudi Arabia by applying it to a sample of bachelor's and graduate students at the college of Education at umm al-Qura University. The (ESE) was applied to a random sample representing the study population consisting of (216) respondents. The results of the study showed that the scale consists of three main factors, with showed a high degree of construct validity through fit indices of the confirmatory factor analysis. The results have shown a gradual consistency of the measure's invariance that reaches the high level of the Measurement Invariance across the gender and study groups variables.

• Journal of Aerospace System Engineering
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• v.15 no.3
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• pp.20-29
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• 2021

As the feasibility of urban air mobility (UAM) service using electric vertical take-off and landing (eVTOL) aircraft increases due to aircraft electrification, distributed propulsion, and artificial intelligence technologies, the U.S. and European aeronautical societies have been improving their certification system and regulations for the type certification of eVTOL. The improved certification system is expected to be ready in the near future, after the European Union Aviation Safety Agency (EASA) proposed the VTOL Special Condition, SC-VTOL in 2019. However, the current domestic certification system is still insufficient to properly respond to eVTOL. This study investigated the development trends of foreign eVTOL and certification systems, identified considerations to improve the domestic certification system, and proposed the measures for type certificates and type certificates validation of eVTOL based on the comparison between SC-VTOL and Korea airworthiness standards (KAS).