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Currency Substitution in Indonesia
No full text本文利用資產組合模型探討印尼是否有通貨替代的現象，又在金融危機發生後至今日，匯率對民眾貨幣需求的影響是否有異於過去。在考量通貨替代情況下，貨幣需求函數除了包含所得、利率變數外，還包括匯率，此外也加入時間虛擬變數與匯率的交叉項，研究期間則為1996年1月至2006年5月。應用Johansen共整合分析法之實証結果顯示印尼的貨幣需求雖深受匯率所影響，但並不存在通貨替代的現象，且隨著金融風暴陰霾遠去，印尼民眾較願意持有印尼盾。This paper employs monthly data over the 1996-2006 periods to investigate whether currency depreciation in Indonesia has resulted in currency substitution away from Rupiah. To take account of currency substitution, the demand for money that includes the exchange rate in addition to income, interest rate, also an interaction dummy variable between time dummy and exchange rate. The methodology is based on an application of the Johansen and Juselius（1990）cointegration technique. There is no evidence of currency substitution in real M1 equation.第一章 緒論 1
第一節 研究動機與研究架構 1
第二節 通貨替代 6
第二章 文獻回顧 8
第三章 實證模型 16
第一節 實證模型之建立 16
第二節 實證方法 17
第四章 實證結果 23
第一節 資料來源及處理 23
第二節 單根檢定結果 27
第三節 共整合檢定結果 29
第五章 結論 36
參考資料 3
Study of Cold-Sprayed Coatings on IN-738 Superalloy
No full text本研究專注於電廠氣渦輪機高溫區段IN-738葉片之冷噴銲塗層製程探討。一般而言，電廠基於成本考量，每隔固定時間即會進行氣渦輪機之檢修，將受損之動葉片進行銲補再生。先進之雷射銲補製程係採用雷射同軸輸送IN-738粉末至葉片受損區域，唯預熱溫度需達到800℃以上方可得到良好的銲補效果，製程較為複雜且耗時。冷噴銲具有銲補速度快且塗層孔隙率低的特性，若應用於IN-738葉片之銲補，可能取代部份銲補再生製程。
實驗結果顯示，IN-738粉末在氮氣載流氣體溫度780至830℃間，噴銲於IN-738基材上可獲得良好的塗層。金相觀察顯示IN-738塗層與基材有良好之接合，且孔隙率相當低(<5％)。SEM更可觀察到粉末邊緣之絕熱剪切應變區，此區為粉末間或粉末與塗層之重要鍵結機制。TEM觀察發現塗層有奈米級細晶區與粗晶區，證明粉末外圍(晶粒較細)與中心(晶粒較粗)所受到之塑性變形量有極大差異。塗層若經過熱處理，內部有γ΄析出，與IN-738基材類似。若經1205℃/10 min熱處理(模擬硬銲製程)後，奈米晶粒消失，並可觀察到不規則形狀之γ΄ (~200 nm) 析出，粉末間之γ΄則較為粗大，此係因粉末邊緣為快速擴散路徑，γ΄成長較為快速。若經1180℃/2 h + 850℃/16 h熱處理，內部呈現方型(邊長200 nm)與圓型(直徑50 nm)兩類型之γ΄，此與IN-738基材經二段式熱處理者相同。此外，粉末間為連續型之γ΄，鈮和鉈的含量較多，故亦為碳化物成核之位置。XRD分析As-sprayed塗層繞射峰並與粉末相較，發現前者γ之半高寬變寬且峰值往低角度偏移。此現象乃因IN-738粉末受到高速衝擊，使塗層晶粒細化、差排密度與氧含量上升所致。IN-738冷噴銲塗層經熱處理後，塗層內γ΄之析出使基地內Al、Ti原子濃度下降，晶格常數變小，繞射峰往高角度移動，此現象在IN-738粉末與冷噴銲塗層中皆可觀察到。試片經不同熱處理後，因γ΄析出非常快速，故峰值角度上差異不大。冷噴銲塗層厚度可達0.5mm，有可能取代IN-738 + DF4B之硬銲再生製程，並可避免因DF4B所導致之硬脆鉻硼化合物的生成，具有相當的應用價值。IN-738 nickel-base superalloy has been widely utilized for fabricating hot-section components, e.g., turbine blades, in the industrial gas turbines. The purpose of this study was to investigate the cold spray process and the coating properties of IN-738 powder on an IN-738 substrate. During recent years, the laser cladding process has been used in power plants to restore damaged turbine blades and has proven to be cost effective. However, the drawback of such a process is that the turbine blades need to be heated to high temperatures; in addition, the process is complicated and time consuming. Satisfactory coatings can be obtained on a workpiece by using the cold spray process, which is a fast process to produce low-porosity coatings.
Experimental results revealed that IN-738 powder could be sprayed on an IN-738 substrate using nitrogen carrier gas at 780~830℃. Metallographic analysis revealed that the coatings had low coating porosity (<5%) and good adhesion to the substrate. In addition, SEM examinations revealed the formation of an adiabatic shear strain zone at the outer layer of the powder particles. The adiabatic shear strain zone is the main mechanism that governs the bonding of the powder particles as well as the coatings to the substrate. TEM observations confirmed that the coatings had a nanograin zone and a coarser grain zone. The diffraction patterns revealed that the nanograin zone occurred at the outer layer of the powder particles and that the coarser grain zone occurred at the inner portion. These results implied that the difference in plastic deformation between the outer and inner portions of the powder particles was substantial. After a heat treatment of 1205℃/10 min (similar to a brazing process), the formation of irregular shaped γ΄ precipitates (~200 nm) the absence of nanograins in the coatings were resulted. Moreover, the coarsening of γ΄ at inter-particle regions was obvious due to fast surface diffusion. When the coatings subjected to a two-step treatment (1180°C/2 h + 850℃/16 h), γ΄ precipitates of either cubical (200 nm edge length) or spherical particles (50 nm diameter) were observed. Such microstructral features were similar to those of the IN-738 substrate after the same heat treatment. The inter-particle regions, which had higher contents of Ta and Nb, were likely to be the nucleation sites for carbides. Additionally, continuous γ΄ precipitates were formed along the inter-particle regions. X-ray diffraction (XRD) analysis was also performed on the raw powder as well as the as-sprayed coatings. The results indicated that the γ peaks obtained for the as-sprayed coatings shifted to lower angles and also broaden relative to the peaks obtained for the raw powder. This phenomenon could be attributed to the presence of fine grains, high dislocation density and increased oxygen content in the coatings. After heat treatment of the coatings or the raw powder, the formation of γ΄ lowered the lattice parameter of γ owing to reduced Al and Ti concentrations in the matrix, i.e., the peaks moving toward the higher angles. A comparison of the coatings after different heat treatments revealed that the diffraction peaks were nearly unchanged. This could be due to the fact that the rate of γ΄ precipitation was fast and less dependent on the heat treatment. By using the cold spray process, coatings with thicknesses of 0.5 mm can be obtained. This process also has the advantage over the brazing process (using IN-738 + DF4B powder mixtures brazed at 1205℃/10 min) to eliminate the formation of brittle chromium borides in the coatings. It is clear that the cold spray process can have many new applications and can possibly replace the brazing process for restoring turbine blades, in particular, refurbishing worn surfaces of the turbine blade
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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