• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.246-256
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• 2018

Graphene oxide (GO) reinforced Polyvinyl chloride (PVC)-Waterborne Castor Alkyd (WCA) nanocomposites (PVC/WCA/GO) films were processed through solution blending technique. TGA showed that the thermal stability of PVC/WCA/GO-0.5 films was better than that of PVC/WCA blend film. With incorporation of 0.5 wt.% GO, the tensile strength and elastic modulus of the blend nanocomposite have significantly improved by about 260% and 185%, respectively, compared with neat polymer. The physicomechanical properties of these films suggest that the PVC/WCA/GO nanocomposite films may have a potential scope for their application in packaging industries. The results are supported by characterizations like FTIR, XRD, TEM and FESEM.

• 비교문화연구
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• 제20권
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• pp.211-224
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• 2010

In David Henry Hwang's M. Butterfly and Shirley Lim's Joss and Gold, two Asian-American texts exploring the relationship between America and Asia, the classic Orientalist motif of the infinitely submissive oriental female is reworked to articulate an Asian response to American hegemony. Both works mobilize the Asian female as a figure of contestation to destabilize and reconceptualize the patriarchal and Orientalist strategies of Western cultural and political domination. This paper explores the tactically different though strategically similar counter-discursive moves adopted in the two works to suggest a broader cultural realignment in Asian-American relations.

• 중국학논총
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• 제68호
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• pp.1-28
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• 2020

本論文的目的在於探討古代漢語變調構詞的音義關係在閩南語詞典《廈新典》的文白異讀當中如何傳承下來。本研究尤其關注古代漢語的變調構詞與《廈新典》文白異讀的音義關係之間擁有緊密聯繫的七個例子, 並把此七例分成兩類, 《廈新典》中的"讀"字, "孫(遜)"字保留了與變調構詞完全一致的音義關係, 此類例子也保留了與現代漢語完全一致的音義關係。《廈新典》中的"塞"字, "取(娶)"字, "厭"字, "喪"字, "勞"字表示與變調構詞緊密的音義對應關係, 但是我們也能發現部分文讀音或者白話音的音義關係中略有出入。從變調構詞的觀點把《廈新典》中文白異讀音義關係的錯誤做了比較, 查到了《廈新典》中有關文讀音音義關係釋義的錯誤有9例, 有關白話音音義關係的錯誤有3例, 前者比後者的錯誤多達4倍。另外, 《廈新典》中義項的錯誤發生次數爲9次, 《臺多音》中義項的錯誤發生次數爲3次。此統計數字反映了與上古漢語有密切關係的白話音層次與中古漢語時期以來屢次持續傳入閩方言層次的差異。我們認為這些錯誤與英國牧師甘爲霖編著《廈新典》的目的應該有密切關係。

• 대한수학회보
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• 제60권4호
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• pp.863-872
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• 2023

Let n ⩾ 2 be an integer, we denote the smallest integer b such that gcd {(ⁿ_k) : b < k < n - b} > 1 as b(n). For any prime p, we denote the highest exponent α such that p^α | n as v_p(n). In this paper, we partially answer a question asked by Hong in 2016. For a composite number n and a prime number p with p | n, let n = a_mp^m + r, 0 ⩽ r < p^m, 0 < a_m < p. Then we have $$v_p\(\text{gcd}\{\(n\\k\)\;:\;b(n)1\}\)=\{\array{1,&&a_m=1\text{ and }r=b(n),\\0,&&\text{otherwise.}}$$

• Structural Engineering and Mechanics
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• 제87권4호
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• pp.363-373
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• 2023

Since the first family of structure-dependent methods can simultaneously integrate unconditional stability and explicit formulation in addition to second order accuracy, it is very computationally efficient for solving inertial problems except for adopting auto time-stepping techniques due to no nonlinear iterations. However, an unusual stability property is first found herein since its unconditional stability interval is drastically different for zero and nonzero damping. In fact, instability might occur for solving a damped stiffness hardening system while an accurate result can be obtained for the corresponding undamped stiffness hardening system. A technique of using a stability factor is applied to overcome this difficulty. It can be applied to magnify an unconditional stability interval. After introducing this stability factor, the formulation of this family of structure-dependent methods is changed accordingly and thus its numerical properties must be re-evaluated. In summary, a large stability factor can result in a large unconditional stability interval but also lead to a large relative period error. As a consequence, a stability factor must be appropriately chosen to have a desired unconditional stability interval in addition to an acceptable period distortion.

• Structural Engineering and Mechanics
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• 제91권2호
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• pp.197-209
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• 2024

The vibration of elastically supported bidirectional functionally graded (BDFG) sandwich beams on an elastic foundation is investigated. The sandwich structure is composed of upper and lower layers of BDFG material and the core layer of isotropic material. Material properties of upper and lower layers are assumed to vary continuously along the length and thickness of the beam with a power-law function. Hamilton's principle is used to deduce the vibration equations of motion of the sandwich Timoshenko beam. Then, the partial differential equation of motion is spatially discretized into a time-varying ordinary differential equation in terms of Chebyshev differential matrices. The eigenvalue equation associated with the free vibration is formulated to study the influence of various slenderness ratios, material gradient indexes, thickness ratios, foundation and support spring constants on the vibration frequency of BDFG sandwich beams. The present method can provide researchers with deep insight into the impact of various geometric, material, foundation and support parameters on the vibration behavior of BDFG sandwich beam structures.

• 한국산학기술학회논문지
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• 제13권12호
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• pp.6159-6166
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• 2012

수자원에서 특히 중요한 홍수기에 대한 유량 측정은 어려움이 있고 모든 하천에 대한 지속적인 유량측정은 현재 시스템상에서는 불가능하다. 그래서 유량의 생산을 위해서 그동안 수위유량 관계 곡선이 사용되어 왔다. 하지만 수위-유량 관계 곡선은 그 편리성에도 불구하고 수위와 유량만의 관계를 사용하므로 정확성 면에서 항상 문제가 있어왔다. 따라서 본 연구에서는 Chiu의 엔트로피 개념의 2차원 유속공식을 사용하여 새로운 평균유속공식을 유도하였다. 본 공식은 수심, 중력가속도, 동수경사, 에너지경사, 동점성 계수 등 하천의 수리적 특성을 잘 반영하고 최대유속도 산정할 수 있다. 또한 최대유속과 평균유속사이의 선형관계를 검증할 수 있었고 그 결과로써 하천단면의 특성을 잘 나타내는 평형상태의 ${\phi}(M)$을 산정하였다. 평형상태의 ${\phi}(M)$을 사용하여 평균유속을 산정하였고 이를 바탕으로 유량을 산정하였다. 본 공식의 검증을 위해서 고리형 특성을 보이는 부정류 상황에서의 실험실 측정 데이터를 사용하여 계산된 유량과 실측된 유량을 비교하였고 그 결과는 매우 잘 일치함을 알 수 있었다. 향후 다양한 실험실 데이터 및 하천 데이터를 이용하여 연구가 지속되어 진다면 수자원 분야에 널리 이용될 것으로 판단된다.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.87-96
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• 2020

유속은 수리학적 구조물을 운영 관리하는데 필수적인 요소임에도 불구하고 경제적, 인력적 이유로 인해 유량, 유속 측정이 충분히 이루어지지 않고 있다. 또한, 홍수기에 하천의 유속을 산정하는데 사용되는 공식은 Chezy와 Manning 등류 공식으로 일반적으로 등류가 아닌 자연하천에 이 공식을 그대로 사용하는 것은 문제가 있다. 이에 따라 본 연구는 측정치와 경험적인 방법으로 유량과 유속을 다른 수리학적 요소로 나타내는 방법이 아닌 이론적 방법으로 유속에 접근하였다. 이전의 기존 유속 공식과 분포식의 한계를 엔트로피 이론으로 해결한 Chiu (1987)의 연구를 따라 개수로의 유속을 엔트로피 이론에 근거하여 전개하였고 효용성을 검증하기 위해 지점의 유속이 측정된 수로의 데이터를 활용하여 식을 검증하였다. 이동거리의 R2값은 0.9993, 유속의 R2값은 0.8051~0.9483으로 예측치가 실제 적용 가능함을 확인하였다. 식을 활용하면 실제 유속 측정을 여러 지점에서 매시간 하지 않아도 특성 인자를 통해 시간에 따라 이동하는 하천의 유속과 이동지점을 동시에 구할 수 있고 실시간 유속이 필요하지만 빈번한 실측이 불가능한 홍수기의 유속 산정이 가능하다. 이를 활용하여 하천의 수평·수직거리를 이용해 제작되는 하천 종단면도에 활용 가능하며 GIS와 연계하여 하천 특성인자의 정확성을 높일 수 있을것으로 판단된다. GIS의 공간 모델에 하천의 거리와 유속 정보를 결합해 홍수기의 경보·예측 시스템에 활용이 가능할 것으로 보인다.

• 수완나부미
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• 제4권1호
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• pp.57-90
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• 2012

This essay is for a study on the survey of buddhist cultural literary document about the Southeast Asia by Nanqishu(南齊書), Liangshu(梁書), Chiu T'angshu(舊唐書), Hsin T'ang shu(新唐書) which are included in the Chinese Official History and Jí-shénzhōu-sānbăo-găntōng-lù(集神州三寶感通錄), Weioshu Shilao Ji (魏書 釋老志). These documents allows us to imagine next some historical states. First, these documents are recording this area, especially Funan, as a plentiful diggings of gold, silver, tin, copper, etc. These are important materials for gilt bronze sculptures. Further, this local produced gold called 'Yangmai(楊邁)' is recognized as same as Zĭmòjīn(紫磨金) in china, and these documents explains the process of producing the bronze images and golden ornaments in Southeast Asia. Specially, this plentiful materials leads them to make a 10 wei(圍) tall golden-silver image which worshiped as hindu god or sometimes buddhist images. Second, Vietnam and Funan in Northern and Southern Dynasty periods were in antagonistic relationship not only in the political but also in religious between Vietnamese Hinduism and Funan's Buddhism. Under this situation, the monk Nagaxian(那伽仙) who had came from India was accredited to Southern Qi court as a delegate to build a good relationship by the common religion Buddhism. It means the Buddhism of Southeast Asia also took a role of diplomacy. Third, these documents proved the active Southeast Asian cultural exchange in early 3th century. At this time, Funan delegate Suwu(蘇物) visited the court of Kushan Dynasty in India and he is seemed to travel the city of Pātaliputra. It oppressed us to extend our outlook which have been restricted in the relationship between Southern india and Southeast Asia to more broaden area. In addition, the buddhist art of Southern India and Bodhgaya temple was imported to Southeast Asia directly to send to Southern China. For example, the wooden buddha image, Bodhgaya stupa image, and Sri Lanka style's buddha images are looked be introduced to Southern China at this time throughout the Southeast Asia. At last, we got to know that the court music of Kucha in the northern silk route was imported to the Southeast Asia in early middle age. Even it may be introduced by China, but this document is very important to make the surmise is not unreasonable that the buddhist culture of northern silk route imported to the Southeast Asia accompanied with Kucha music. The buddha images in Gandharan style which are excavated from some site of Southeast Asia may demonstrate this literary sources is authentic.

• Journal of Construction Engineering and Project Management
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• 제5권3호
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• pp.1-9
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• 2015

Project cost is an important concern in any construction project. Although there has been a lot of studies on factors affecting the cost of construction projects, there seems no consensus as what cost factors have direct influence on the cost of civil engineering projects. This study therefore aims to bridge the current knowledge gap by examining quantity surveyors' perception of the factor structure among nineteen costing attributes identified based on literature review. Questionnaire was used to elicit responses from quantity surveyors working in the Hong Kong construction industry. Principal component analysis is conducted to extract the factor structure of the cost attributes and the attributes are grouped into three factor components, namely the contract management factor, the project management factor and the monetary value factor. Understanding these cost impact factors could be crucial in managing civil engineering projects, since it allows the project stakeholders and quantity surveyors to take precautionary steps to identify the cost management problems and areas for improvement and could even help to avoid cost deviations in engineering projects.