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The purpose of this paper is a development of a virtual flight test framework with derivative design optimization. Aircraft manufactures and engineers have been putting significant effort into the design process to lower the cost of development and time to a minimum. In terms of flight tests and aircraft certification, implementing simulation and virtual test techniques may be a sufficient method in achieving these goals. In addition to simulation and virtual test, a derivative design can be implemented to satisfy different market demands and technical changes while reducing development cost and time.

In this paper, a derivative design optimization was applied to Expedition 350, a small piston engine powered aircraft developed by Found Aircraft in Canada. A derivative that changes the manned aircraft to an Unmanned Aerial Vehicle for payload delivery was considered. An optimum configuration was obtained while enhancing the endurance of the UAV. The multidisciplinary design optimization module of the framework represents the optimized configuration and additional parameters for the simulator. These values were implemented in the simulator and generated the aircraft model for simulation. Two aircraft models were generated for the flight test.

The optimization process delivered the UAV derivative of Expedition E350, and it had increased endurance up to 21.7 hours. The original and optimized models were implemented into virtual flight test. The cruise performance exhibited less than 10 per cent error on cruise performance between the original model and Pilots Operating Handbook (POH). The dynamic stability of original and optimized models was tested by checking Phugoid, short period, Dutch roll and spiral roll modes. Both models exhibited stable dynamic stability characteristics.

The original Expedition 350 was generated to verify the accuracy of the simulation data by comparing its result with actual flight test data. The optimized model was generated to evaluate the optimization results. Ultimately, the virtual flight test framework with an aircraft derivative design was proposed in this research. The additional module for derivative design optimization was developed and its results were implemented to commercial off-the-shelf simulators.

This paper proposed the application of UAV derivative design optimization for the virtual flight test framework. The methodology included the optimization of UAV derivative utilizing MDO and virtual flight testing of an optimized result with a flight simulator.

With the advancements in electric vertical take-off and landing (eVTOL) aircraft technology such as batteries, mechanisms, motors, configurations and so on, designers and engineers are encouraged to create unique and unconventional configurations of eVTOL aircraft to provide better capabilities and higher efficiencies to compete in the market. The box fan-in-split-wing tiltrotor eVTOL aircraft is an innovative design that aims to address the aerodynamic inefficiencies such as propeller effects in cruise and engine mounts drag that existed in traditional eVTOL aircraft designs such as vectored thrust, rotorcraft, lift + cruise and multi-copter configurations. This paper aims to propose a multi-disciplinary design process to conceptually design the box fan-in-split-wing Tiltrotor eVTOL aircraft.

An unconventional methodology was used to design the UAM aircraft, and the following parameters are considered: capable of vertical take-off and landing, highly aerodynamic with a high lift-to-drag ratio, low Cd₀ modern and appealing, rechargeable or battery swappable and feature to minimise or negate propeller drag. A heavy emphasis on improving performance and weight based on aerodynamics was enforced during the conceptual design phase. MAPLA and XFOIL were used to identify the aerodynamic properties of the aircraft.

Upon determining the key parameters and the mission requirements and objectives, a list of possible VTOL configurations was derived from theoretical and existing designs. The fan in the wing/split wing was selected, as it could stow the propellers. A tiltrotor configuration was selected because of its ability to reduce the total number of lift props/motors, reducing powerplant weight and improving aerodynamic efficiency. For the propulsion configuration, a battery–motor configuration with a hexa-rotor layout was chosen because of its ability to complement the planform of the aircraft, providing redundant motors in case of failure and because of its reliability, efficiency and lack of emissions. Coupled with the fan-in-wing / split wing concept, the box wing seamlessly combines all chosen configurations.

The box fan-in-split-wing Tiltrotor eVTOL aircraft aims to address the aerodynamic inefficiencies of earlier designs such as propeller effects in cruise and engine mounts drag. The potential benefits of this aircraft, such as increased range, endurance and payload capacity, make it an exciting prospect in the field of Urban Air Mobility.

The ground control station (GCS) is an important part of unmanned aerial vehicles (UAVs) which provides the facility for human control. In previous work, the authors developed an enhanced virtual reality GCS (VR-GCS) for airships. Here, the authors incorporated haptic gloves to control the aerial vehicle with the use of a virtual controller defined within the virtual environment.

The VR headset was connected to the haptics and the flight simulation tool. The VR headset was used to visualize basic flight simulation while the vehicle was controlled via the haptic gloves and a virtual controller defined in the virtual environment. Here, using the previous experience, the position and orientation data from the VR headset was sent to the FlightGear flight simulator (FGFS) via extensible markup language codes. This was used to drive the heads-up-display (HUD) as well within the VR headset. Then, the inputs from the pilot on the virtual controller were sent to the FGFS using an embedded code. To accurately simulate the final goal of deploying the haptic-based VR solution to monitor and pilot the airship in beyond visual line-of-sight scenarios, a VR application was developed using the Unity game engine. Finally, the integration of VR, haptics and FGFS was performed using another embedded code.

A test procedure was conducted with a similar rating technique based on the NASA TLX questionnaire that identifies the pilot’s spare mental capacity when completing an assigned task to assure the comfortability of the proposed haptics VR-HMD (HVR-HMD). Accordingly, 10 users participated in the test and a comparison has been made for the aircraft control using the physical remote control (RC) controller and the virtual one. The results from the repeated measures analysis of variance and Tukey’s honestly significant difference post hoc tests revealed significant differences in mental demand, physical demand, effort and frustration across the different simulation conditions. Notably, the HVR-HMD system significantly lowered workload and frustration levels compared to both the desktop and VR-HMD setups, underscoring its effectiveness as a training tool. Results from the NASA TLX questionnaire showed that the current iteration of the system is ideal for training amateur users to replace traditional RC controllers by using similar virtual systems in a safe and immersive environment.

Such an advanced portable system may increase the situational awareness of pilots and allow them to complete flights with the same data transmission procedures using virtual systems in simulation.

The purpose of this paper is to assess and determine the potential of augmented reality (AR) in aerospace applications through a survey of published sources.

This paper reviews a database of AR applications developed for the aerospace sector in academic research or industrial training and operations. The review process begins with the classification of these applications, followed by a brief discussion on the implications of AR technology in each category.

AR is abundantly applied in engineering, navigation, training and simulation. There is potential for application in in-flight entertainment and communication, crew support and airport operations monitoring.

This paper is a general review introducing existing and potential AR applications in various fields of the aerospace industry. Unlike previous publications, this article summarizes existing and emerging applications to familiarize readers with AR use in all of aerospace. The paper outlines example projects and creates a single comprehensive reference of AR advancements and its use in the aerospace industry. The paper provides individuals with a quick guide to available and emerging technology.

This paper aims to examine how the relationship between abnormal audit fees and audit quality changed after adoption of the International Financial Reporting Standards (IFRS) in Korea.

Using empirical data collected over the period from 2008 to 2013, this study analyzes the association between abnormally high/low audit fee and audit quality. This study uses linear regression to test the hypothetical relation using discretionary accrual as a proxy for audit quality.

This study finds that there exists no significant relationship between abnormally high audit fees and audit quality measured by the magnitude of discretionary accruals in the pre-IFRS adoption period. However, the relationship between abnormally high audit fees and the magnitude of discretionary accruals turns to be positive in the post-IFRS adoption period. These finding suggests that the IFRS enables some clients to engage more discretion in the choice of discretionary accruals and auditors charge higher audit fees in return for allowing the discretion for such clients.

This study provides insight to regulators of the need to review carefully the financial statements of firms with abnormally high audit fees, and to investors to be more cautious when using financial information about these firms.

To the best of authors’ knowledge, this is the first study to assess IFRS impact on audit fee-quality relation. Also, unique Korean audit market with intensifying competition and discounting audit fee provides interesting setting to review the impact of abnormal audit fee on audit quality.

After the Korean War, South Korean politics was dominated by national security concerns. Reversing Carl von Clausewitz's well-known dictum, in South Korea, “politics is the continuation of war by other means.” Until the late 1980s, politics in South Korea was far from democratic. South Korea had five direct presidential elections (1987, 1992, 1997, 2002, and 2007) and six national assembly elections (1988, 1992, 1996, 2000, 2004, and 2008) after the democratic transition of 1987. In 1992, a civilian candidate, Young Sam Kim, was elected president. Young Sam Kim (1993–1998) prosecuted and punished former generals turned presidents Doo Hwan Chun (1980–1988) and Tae Woo Roh (1988–1993) for corruption, mutiny and treason in 1995. Dae Jung Kim (1998–2003) was elected president in 1997. For the first time in South Korean political history, regime change occurred between a ruling party and an opposition party.

In this chapter, the change and continuity of civil–military relations through the fluctuating dynamics of the democratic transition and consolidation in South Korea is examined. A positive consolidation of democratic reform is one that, while securing indisputable civilian supremacy, grants the military enough institutional autonomy for the efficient pursuit of its mission. Civilian supremacy should be institutionalized not only by preventing military intervention in civilian politics but also by ensuring civilian control over the formation and implementation of national defense policy.

In sum, despite three terms of civilian presidency, civilian supremacy has not yet fully institutionalized. Although significant changes in civil-military relations did occur after the democratic transition, they were not initiated by elected leaders with the intention of establishing a firm institutional footing for civilian supremacy. South Korea's political leaders have not crafted durable regulations and institutions that will sustain civilian control over the military.

More than six decades, Korea is still divided. The most highly militarized zone in the world lies along the demilitarized zone. How to draw the line prudently between seeking national security and promoting democracy shall be the most delicate task facing all the civilian regimes to come in South Korea. That mission will remain challenging not only for civilian politicians but also for military leaders.

The puzzle of underwriting cycles and insurance crises in property-liability insurance has led to numerous economic hypotheses and analyses, yet no single theory seems capable of explaining all of its aspects. Reinsurance is hypothesized to be a potential factor in observed cycles in the primary market; despite this, few underwriting cycle studies focusing on reinsurance exist. The purpose of this research is to apply two principal underwriting cycle theories: the capacity constraint and risky debt hypotheses, to non-proportional property and casualty reinsurance in the U.S. Non-proportional reinsurance is highlighted, since it is designed to cover the tail of the loss distribution and is considered to be relatively riskier than proportional reinsurance as a result. Two professional U.S. reinsurer samples are studied, one for property and one for casualty; U.S. reinsurers in each sample were chosen on the basis of their non-proportional property (casualty) writings. The sample period is 1991 to 1995. The results support both the capacity constraint hypothesis and the risky debt hypothesis, and this is the first research to do so. A major innovation in this study is the use of capacity variables that are broken down by major region of the world

The purpose of this paper is to study the consideration of uncertainty from analysis modules for aircraft conceptual design by implementing uncertainty-based design optimization methods. Reliability-Based Design Optimization (RBDO), Possibility-Based Design Optimization (PBDO) and Robust Design Optimization (RDO) methods were developed to handle uncertainties of design optimization. The RBDO method is found suitable for uncertain parameters when sufficient information is available. On the other hand, the PBDO method is proposed when uncertain parameters have insufficient information. The RDO method can apply to both cases. The RBDO, PBDO and RDO methods were considered with the Multidisciplinary Design Optimization (MDO) method to generate conservative design results when low fidelity analysis tools are used.

Methods combining MDO with RBDO, PBDO and RDO were developed and have been applied to a numerical analysis and an aircraft conceptual design. This research evaluates and compares the characteristics of each method in both cases.

The RBDO result can be improved when the amount of data concerning uncertain parameters is increased. Conversely, increasing information regarding uncertain parameters does not improve the PBDO result. The PBDO provides a conservative result when less information about uncertain parameters is available.

The formulation of RDO is more complex than other methods. If the uncertainty information is increased in aircraft conceptual design case, the accuracy of RBDO will be enhanced.

This research increases the probability of a feasible design when it considers the uncertainty. This result gives more practical optimization results on a conceptual design level for fabrication.

It is RBDO, PBDO and RDO methods combined with MDO that satisfy the target probability when the uncertainties of low fidelity analysis models are considered.