2,087 research outputs found
Will the New-style Currency Decrease Counterfeiting?-The Effect of Withdrawal Policy
No full text一國政府為保有鑄幣利得，常以發行新版鈔票來解決?鈔問題。而各國施行鈔票改版政策所採取的舊鈔回收規定迥異，例如是否設定回收截止期限，以及執行回收機構的多寡等，都將使得回收舊鈔兌換新鈔的速度不同。本文以貨幣搜尋模型探討不同的舊鈔回收規定如何影響鈔票改版政策解決?鈔問題的有效性，以及?鈔問題獲得解決的時點。我們發現，當糾舉?鈔、回收舊鈔的績效太低，發行新版鈔票無法解決?鈔問題；足夠的糾舉績效是杜絕?鈔的關鍵。若政府採行的舊鈔回收規定可迅速回收舊鈔，則鈔票改版解決?鈔問題的政策效果將較早發生。不過，政府若看到?鈔數量減少便過早判定?鈔問題已銷聲匿跡，而提早回收截止期限甚至降低查緝?鈔的努力，都可能使?鈔問題死灰復燃。A common policy to decrease counterfeiting is to introduce new-style currency that is harder and more expensive to counterfeit. Upon introducing new-style currency, government may withdraw old-style currency from circulation with or without imposing a deadline for private holders to exchange old-style money for new-style. The withdrawal policy affects the length of time it takes for the removal of old-style currency to be completed and, thus, have impacts on the effectiveness of decreasing counterfeiting. We use a random matching model to study the effect on stopping counterfeiting of different withdrawal policies accompanying the issue of new-style currency. We find that, if the enforcement effort against counterfeiting is not high enough, the introduction of new-style currency will not achieve a steady state where counterfeiting is eliminated. If government withdraws old-style currency more aggressively, it takes a shorter time to eliminate counterfeiting. However, seeing the counterfeit money start to decrease, government should not make a premature judgment that the policy of eliminating counterfeiting has achieved its purpose. If government wrongly makes the judgment and decreases its effort in confiscating counterfeit money as well as withdrawing old-style currency, the counterfeiting problem may resume
A new preconditioned AOR iterative method for L-matrices
No full textAbstractLi et al. [Y.T. Li, C. Li, S. Wu, Improvements of preconditioned AOR iterative methods for L-matrices, J. Comput. Appl. Math. 206 (2007) 656–665] have considered the modified AOR method with a preconditioner (I+Sα). In this paper, we present a new preconditioner (I+Sαβ) instead of (I+Sα). The comparison theorems and numerical experiments show that the proposed new method can achieve faster convergence than the preconditioner introduced by Li et al
Genetics structure and phylogenetic relationships of conserved Taoyuan pigs and exotic pig breeds
No full textThe effect of dislocation density on the interactions between dislocations and twin boundaries in nanocrystalline materials
No full textThe interactions between dislocations and twinboundaries (TBs) are significantly affected by both intrinsic material properties and extrinsic factors, including stacking fault energy, the energy barriers for dislocation reactions at TBs, twin thickness and applied stress. In this study, dislocation–TB interactions in grains with different dislocationdensities were investigated and we conclude that the dislocationdensity also affects the dislocation–TB interactions. In a twinned grain with a low dislocationdensity, a dislocation may react with a TB to fully or partially penetrate the TB or to be absorbed by the TB via different dislocation reactions. Alternatively, in a twinned grain with a high dislocationdensity, dislocations tangle with each other and are pinned at the TBs, thereby making it unfavourable for further dislocation reactions to mediate dislocation penetration across the TB. This leads to an accumulation of dislocations at the TBs, raising the local strain energy, which, in turn, is released by the activation of secondary twins by partial dislocation emissions from the other side of the T
Confirmed genetic component of Taiwan black pigs, Taoyuan pigs, and external pigs by microsatellit markers
No full textThe effect of adding rice husk ash (RHA) and calcined shell powder (CSP) on the properties of cement mortar
No full textTo enhance sustainability in the construction industry, incorporating rice husk ash (RHA) as a partial cement replacement is widely encouraged. Additionally, bio-shells, rich in CaCO₃, pose environmental challenges when improperly discarded, leading to pollution and negative impacts on surrounding communities. This study integrates the beneficial properties of these two waste materials for use in construction. While the effects of RHA on cementitious materials have been extensively studied, limited research has examined the combined influence of RHA and calcined shell powder (CSP) as a partial cement replacement. To explore their potential, RHA and CSP were blended in varying proportions to produce RHA-CSP cement mortar. Experimental results demonstrated that the R15S10 mix achieved the highest mechanical performance by optimizing the balance between pozzolanic reactivity and the filler effect. As hydration progressed, the pozzolanic reaction intensified under high pH conditions, increasing the C-S-H dehydration peak while reducing the CH decomposition peak. Additionally, the incorporation of CSP and RHA refined the pore structure and decreased overall porosity, enhancing mortar compactness. By utilizing these waste materials to create an optimized mix, this study supports the sustainable application of discarded shells and rice husks in construction
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