郭重辰 博士 / 教授 / 飛行員 的部落格

飛行失事的因素概分為：人為(Human)、機械(Technical)、環境(Environment)、組織(Organization)及其他無法歸類肇事原因或資料不足等五大類因素，大部份失事是人為因素所導致。無人機(Unmanned Aircraft System, UAS)的發展從軍事用途到民間應用，目前已有無人機用於載運少量貨物，未來有可能出現無人駕駛大型飛機，無人機儼然成為未來趨勢。本研究之動機是探討無人駕駛能否代替人為操控民航客機？是否能被旅客接受？研究目的為探討無人駕駛民航客機(Unmanned Commercial Aircraft, UCA)的可行性，並分析乘客對於無人駕駛取代機師操控客機的接受程度。本研究利用現有無人機相關技術、法規和人為錯誤理論作為理論基礎，採用深度訪談法( In-Depth Interview )訪談專家學者，並以焦點團體訪談法和具有相關背景知識的團體深入討論此議題。本研究假設使用無人駕駛取代飛行員應可大幅減少事故發生，民眾應能日漸接受無人操控的科技與環境。然而本研究發現專家和旅客的意見趨近一致，目前無人駕駛民航客機尚未成熟。雖然過去的失事多數由人為因素所致，但是研究結果發現：(1) 目前無人駕駛技術日漸成熟，但僅停留在探索性研究，因涉及生命安全與飛航安全，在尚無實際成功案例的情況下，旅客接受程度不高。(2) 無論電腦操控技術如何進步，沒有機師現場處理與即時救援，遇到特殊緊急狀況時恐無法及時處理，旅客較無安全感。(3)旅客擔心電腦故障或發生意外時，沒有機師在駕駛艙緊急應變，遠端操控可能無法及時讓飛機回復到安全狀態，因此旅客對於無人駕駛技術完全取代人為操控欠缺信心，導致搭乘意願不高。(4) 電腦通訊網絡可能遭駭客入侵，恐造成遠端操控劫機，須加以防範。(5)現今法令規定要有兩位機師值勤，可先從法令上修改為一位機師值勤，另一位由電腦AI代替，逐步發展無人駕駛民航客機。(6) 近期推出無人駕駛空中計程車進入市場，倘若發生意外，無人客機的發展將受挫停滯，甚至倒退。(7) 無人駕駛貨機相較之下可行性較高，無人駕駛民航客機市場尚未成熟，旅客接受度不高，宜審慎評估循序漸進。本研究建議可以開始著手修訂無人駕駛及無人飛機相關的法規，後續研究可以採用大數據分析，進一步探討旅客對於無人駕駛民航客機市場的接受程度。

關鍵字：人為因素、無人駕駛、深度訪談、焦點團體、法規

本研究挑選文化古都臺南市為例，以複合式多準則決策模式與深度訪談，探討大眾運輸系統組合。六個評估準則為：經濟發展、成本合理、觀光旅遊、環境保育、政治氛圍、執行落實，三項替代方案為：新建地下捷運系統、新建地面輕軌系統、新建高架單軌系統，分別加上現有的公車以及臺鐵，深入探討大眾運輸系統之最佳化組合。使用決策實驗室分析法（DEMATEL）辨識評估準則的因果關係，以分析網路程序法（ANP）評估準則之權重，再以最佳化妥協解方法（VIKOR）找出大眾運輸系統之最佳化組合。在所有評估準則之影響力分析方面，以「政治氛圍」的影響力最大，「執行落實」為影響力的起點，「政治氛圍」權重值最高。「地面輕軌與現有台鐵、公車整合」在六個評估準則都獲得最高分，也是最佳方案。然而深度訪談得知高架單軌為交通工程顧問公司與市府初步規劃方向，建議以新建「環狀輕軌、橫向高架雙向單軌」，並整合現有鐵路與公車路網，組成台南大眾運輸系統。
關鍵詞：多準則決策模式、決策實驗室分析法、分析網路程序法、最佳化妥協解方法、大眾運輸系統。

航空產業從策略規劃到實際營運，運量需求預測都是不容輕忽的重要基礎，常見的方法有時間序列分析、重力模式、灰色理論與類神經網路。本研究使用類神經網路建立多輸入、多輸出之數學模式，與傳統單輸入、單輸出之時間序列分析、灰色理論不同，亦不同於傳統類神經網路為單輸出，僅考慮單一航站或單一航線之模式。本研究可補強時間序列分析與灰色理論不足之處，亦可改善重力模式必須事先確定數學方程式形式與參數之缺點，實證結果指出此模式能準確預測飛航網路運量。
關鍵詞：運量預測、飛航網路、類神經網路

This study reveals the key role of brand equity in customer behavioral intention in an airline service context. An integrated model of air passenger decision-making is established to enhance the current understanding of the relationships between air passenger’s future behavioral intention and its antecedents including service quality, satisfaction and brand equity. The proposed model and hypothesized paths are tested on the survey data collected from air passengers in Taiwan. Empirical results indicate that both brand equity and overall satisfaction mediate the relationship between service quality and behavioral intention. Brand equity may have more effect on behavioral intention than overall satisfaction. Airlines are thus recommended to invest time and resources to build their brand equity, as this is a crucial factor in increasing customer retention and thus achieving long-term profitability and sustained development.
Keywords: Brand equity, Behavioral intention, Service quality, Satisfaction

本研究旨在應用多準則決策模式(MCDM)進行運輸政策決策過程之評估，進而檢驗運輸政策各種準則之間的相依關係。以決策實驗室分析法(DEMATEL)建立影響關係圖(IRM)與網路關係圖(NRM)，探討影響運輸政策決策之因果關係。再以分析網路程序法(ANP)取得準則之權重，接著以最佳化妥協解方法(VIKOR)找出最佳運輸模式。以花蓮對外交通為例，實證結果顯示此模式可有效處理複雜問題，辨識其因果關係，評估準則之優先順序，進而挑選出最佳妥協解。
關鍵詞：運輸政策；多準則決策模式；決策實驗室分析法；分析網路程序法；最佳化妥協解方法

The effect of variable fiber spacing on the supersonic flutter of rectangular composite plates has been investigated using the finite element method and quasi-steady aerodynamic theory. The formulation of the location dependent stiffness and mass matrices due to nonhomogeneous material properties was derived. This study first demonstrates the flutter analysis of composite plates with variable fiber spacing. Numerical results show that the sequence of the natural mode may be altered and the two natural frequencies may be close to each other due to the fiber distribution may change the distributed stiffness and mass of the plate. Therefore, it may change the flutter coalescent modes. It is seen that the flutter boundary may be increased or decreased due to variable fiber spacing. The punch phenomenon on the flutter boundary is obvious in the absence of aerodynamic damping.

This study presents the first vibration analysis of thermally post-buckled hybrid laminates with non-uniformly distributed graphite and E-glass fibers in a single lamina. A 54 degree-of-freedom high order triangular plate element is developed based on the Von Karman large deflection assumption. The formulation of the location dependent linear, nonlinear stiffness and mass matrices due to non-homogeneous material properties, geometrical stiffness matrix due to thermal effects and thermal moment vector due to temperature gradient is derived. The effects of hybrid-fiber distribution on the natural frequencies and mode shapes of thermally post-buckled laminates are discussed. The numerical results reveal that the redistribution of two fibers can considerably decrease the postbuckling deflections of the hybrid laminates and significantly modify the natural frequencies. The stiffening effect of fiber redistribution is more obvious for the laminate with a higher volume fraction index and clamped edges. Special buckling and vibration mode shapes are observed, along with multiple vibration mode shifting. 
Keywords: Vibration; Postbuckling; Temperature; Thermal effect; Hybrid fibers

This study provides the first-known vibration analysis of fully functionally graded carbon nanotube reinforced hybrid composite (FFG-CNTRHC) laminates. CNTs are non-uniformly distributed to reinforce the graphite/epoxy laminates. Some CNT distribution functions in the plane and thickness directions are proposed to more efficiently increase the stiffening effect. The rule of mixtures is modified by considering the non-homogeneous material properties of FFG-CNTRHC laminates. The formulation of the location dependent stiffness matrix and mass matrix is derived. The effects of CNT volume fraction and distribution on the natural frequencies of FFG-CNTRHC laminates are discussed. The results reveal that the FFG layout may significantly increase the natural frequencies of FFG-CNTRHC laminate.
Keywords: Carbon nanotube; Functionally graded; Reinforced; Graphite fiber

This study employs back-propagation neural networks (BPN) to improve the forecasting accuracy of air passenger and air cargo demand from Japan to Taiwan. The factors which influence air passenger and air cargo demand are identified, evaluated and analysed in detail. The results reveal that some factors influence both passenger and cargo demand, and the others only one of them. The forecasting accuracy of air passenger and air cargo demand has been improved efficiently by the proposed procedure to evaluate input variables. The established model improves dramatically the forecasting accuracy of air passenger demand with an extremely low mean absolute percentage error (MAPE) of 0.34% and 7.74% for air cargo demand.
Keywords: forecast; demand; air passenger; air cargo; back-propagation neural networks

Buckling and vibration of composite laminated plates with variable fiber spacing were studied by use of finite element method. The formulation of the location-dependent stiffness matrix due to nonhomogeneous material properties was derived. The results indicate that the more fibers distributed in the central portion of the plate may efficiently increase the buckling load and natural frequencies. The fibers distributed in the outer portion of the plate may increase the critical buckling load. However, they will decrease the natural frequencies due to increasing more mass than stiffness. The fiber distribution may change the stiffness and mass of the plate. Therefore, the sequence of the natural mode may be altered.
Keywords: Fiber spacing; Buckling; Vibration

The effect of shape memory alloy (SMA) on the buckling behavior of a rectangular composite laminate was investigated by the finite element method. The influence of SMA on buckling of composite laminates by varying the SMA fiber spacing was studied. The formulation of the location-dependent stiffness matrix due to non-homogeneous material properties and the temperature-dependent recovery stress stiffness matrix were derived. The results show that the Active Strain Energy Tuning method is much better than the Active Property Tuning method in improving the buckling performance of the plate. When the SMA fibers are concentrated in the center area of the plate, the buckling load of the plate will be improved significantly. If the stiffness of the SMA layer is lower than other layers, the influence of the SMA on the buckling load of the plate will become subordinate.

Thermal buckling behavior of composite laminated plates was studied by making the use of finite element method. The thermal buckling mode shapes of cross-ply and angle-ply laminates with various E1/E2 ratios, aspect ratios, fiber angle, stacking sequence and boundary condition were studied in detail. The results indicate that the high E1/E2 and α2/α1 ratios of AS4/3501-6 and T 300/5208 laminates produce higher bending rigidity along the fiber direction and higher in-plane compressive force in a direction perpendicular to the fiber direction. Therefore, the higher thermal buckling mode shapes are formed. The thermal buckling mode that composite laminated plate will buckle into is mainly dependent on the E1/E2 ratio, α2/α1 ratio, fiber orientation and aspect ratio of the plate.
Keywords: Thermal buckling; Mode shape; Composite laminated plate

An analytical solution is derived for the thermal buckling of a rectangular composite sandwich plate with angle-ply symmetric laminate faces and a honeycomb core. The re-sults show that the buckling mode that sandwich plate will buckle into is dependent on the fiber orientation in the faces and the aspect ratio of the plate. For the square sandwich plate with angle-ply laminated faces, the highest critical buckling temperature is obtained with fibers orientated at 450. For the rectangular [(±)2/ core]s sandwich plate with aspect ratio greater than 2, orientating the fibers in the faces to an angle around 630 will give the highest critical buckling temperature.  
Key words: buckling, composite sandwich plate, shear effect, temperature

By considering that the total transverse displacement of a sandwich plate is the sum of the displacement due to bending of the plate and that due to shear deformation of the core, a 36-degree-of-freedom, high precision, higher-order triangular plate element was developed for the thermal buckling analysis of a rectangular composite sandwich plate. Numerical results show that the buckling mode that a sandwich plate will buckle into is dependent on the fiber orientation in the faces and the aspect ratio of the plate. For the square sandwich plate with angle-ply laminated faces, the highest critical buckling temperature is obtained with fibers orientated at 45°. For the rectangular [(±θ)2/core] s sandwich plate with an aspect ratio greater than 2, orientating the fibers in the faces to an angle around 63° will give the highest critical buckling temperature.
Keywords: Buckling; Composite sandwich plate; Temperature