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遺傳演算法在演化賽局上之應用:策略生態之模擬、計算與分析倪志琦 Unknown Date (has links)
本論文主要是在agent-based計算經濟體系下,利用Holland(1975)所提的遺傳演算法(genetic algorithms)作為計算工具,分別探討連鎖店賽局及寡占市場廠商價格策略的生態演化。
在連鎖店賽局的研究中,藉由agent-based計算經濟分析掠奪性定價的特性,並進一步探討參賽者價格策略的共演化(co-evolutionary)特性,及多元均衡賽局中均衡移轉的動態過程。針對賽局中不同的不確定性進行模擬,結果顯示廠商長期總合行為是否穩定,和賽局中的不確定程度有相當的關聯。另外,弱獨占者和潛在競爭者的價格策略存在著共演化特性。在此演化賽局中,Nash均衡雖非穩定均衡解,但卻最常浮現在長期總合行為中。因此,Nsah均衡對agent-based演化賽局的結果而言,相當具有參考價值。在特定的不確定程度下,長期總合行為似乎只在某些特定的Nash均衡中徘徊。這些移轉途徑並不具有對稱性,甚至移轉速度也非對稱。本研究所呈現的演化結果跳脫一般對均衡的觀念,展現出傳統理論所無法預知的共演化特性,並呈現出非對稱的吸引環。
此外,同樣在Agent-based計算經濟下探討寡占市場廠商策略生態。本研究首先闡明N參賽者囚犯兩難重複賽局和N廠商寡占賽局之間的異同,經由寡占賽局廠商償付矩陣(payoff matrix)的狀態相依馬可夫移轉矩陣( state-dependent Markov transition matrix)性質,說明N廠商寡占賽局和N參賽者囚犯兩難重複賽局的差異。其次,透過三家廠商寡占賽局的模擬實驗,以遺傳演算法建構參賽廠商的適應性行為,分別以寡占市場生態上的表現型(phenotypes)和基因型(genotype)進行分析。20次模擬結果所呈現的最終市場狀態相當分歧,有形成吸引環的三廠商寡占市場、有收斂到價格戰的三廠商寡占市場。另外也成功的模擬出三廠商寡占市場演化至雙佔市場、甚或獨占市場的過程。但是,在眾多模擬中並沒有發現持續的勾結定價狀態,反而掠奪性價格是較主要的價格策略。這些結果相對於實際經濟社會中的寡占市場,給予一個活潑生動的範例。 / Recently, genetic algorithms have been extensively applied to modeling evolution game in agent-based computational economic. While these applications advance our understanding of evolution game, they have generated some new phenomena that have not been well treated in conventional game theory.
In the first topic, we shall systemize the study of one of these new phenomena, namely, coevolutionary instability. We exemplify the basic properties of coevolutionary instability by the chain store game, which is the game frequently used to study the role of reputation effects in economics. In addition, we point out that, while, due to uncertainty effects, Nash equilibria can no longer be stable, and they can still help us predict the dynamic process of the game. In particular, we can see that the dynamic process of the game is well captured by a few Nash equilibria and the transition among them. A careful study can uncover several interesting patterns and we show the impact of uncertainty on these patterns.
In the second topic, the relation between the N-person IPD game and the N-person oligopoly game is rigorously addressed. Our analytical framework shows that due to the path-dependence of the payoff matrix of the oligopoly game, the two games in general are not close in spirit. We then further explore the significance of the path-dependence property to the rich ecology of oligopoly from an evolutionary perspective. More precisely, we simulated the evolution of a 3-person oligopoly game, and showed that the rich ecology of oligopoly can be exhibited by modeling the adaptive behavior of oligopolists with genetic algorithms. The emergent behavior of oligopolists are presented and analyzed. We indicate how the path-dependence nature may shed light on the phenotypes and genotypes coming into existence.
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探討空間記憶之神經行為機制 / Investigation of the Neurobehavioral Mechanisms Underlying Spatial Memory林建佑 Unknown Date (has links)
本研究以神經毒素ibotenic acid破壞不同尾核區域以及鋰鹽去價值程序為操弄變項,觀測此兩種實驗操弄對於大鼠之迷津行為之影響,進而探討標誌系統之行為內涵及神經機制。實驗所採用的作業為線索學習作業以及自我中心作業,分別代表標誌系統下的線索導引策略及體位導向策略。實驗一及實驗二在於檢驗尾核功能缺損對於大鼠迷津行為之影響,從探測嘗試發現大鼠在線索學習的行為表現需依賴砂紙線索的導引,而在自我中心作業之行為則不以環境刺激為依據(實驗一A、二A),顯示大鼠在各迷津作業的行為符合標誌系統的運作原則。神經機制之操弄結果顯示在記憶習得階段,尾核破壞之受試在線索學習作業上的表現並沒有顯著變差,尾核功能缺損並未導致學習的延宕或阻斷,其進步的速度仍與控制組相同(實驗一B)。相較於線索學習作業,尾核破壞之受試在自我中心作業上的表現則明顯變差,幾乎沒有進步的趨勢(實驗二B)。而在記憶保持階段,不管是線索學習作業或自我中心作業之表現皆會因尾核破壞而顯著變差(實驗一C、二C)。實驗三及實驗四則利用鋰鹽去價值程序降低食餌之誘因價值,觀測大鼠行為有無相對應改變。結果發現去價值程序的操弄只會影響到大鼠在自我中心作業的行為表現(實驗四),而不影響其在線索學習作業之行為(實驗三)。由此可知,兩種迷津作業所形成的記憶表徵是不同的,自我中心學習歷程會將增強物表徵在聯結單位中,而線索學習之習得歷程則不會。綜合上述實驗結果,標誌系統下確實有兩個不同空間行為機制,一個為線索導引策略,另一個為體位導向策略,雖皆受到尾核的調節,但調節的程度是不同的。不管是記憶習得或保持階段,尾核在體位導向策略的運作中皆扮演重要的角色,而在線索導引策略只參與了記憶保持歷程的運作。另外,兩個空間行為機制在學習內涵上也不盡相同,以線索導引策略為依據之空間行為會形成刺激反應(S-R)的聯結型態,而以體位導向策略為依據之空間行為則會形成反應及增強物(R-S*)聯結。 / This study investigated the neurobehavioral mechanisms of taxon system of spatial memory through manipulating lesions of subareas in the caudate nucleus by ibotenic acid and lithium chloride (LiCl)-induced reward devaluation. With respect to behavioral measurement in an eight-arm radial maze, a cue learning task and an egocentric task were used for testing the guidance and orientation hypotheses of taxon system, respectively. Data from probing procedures showed that the performance of rats in the cue learning task was impaired when the cue was removed, but the performance in the egocentric task was not affected by changing the context (Experiments 1A and 2A). These results indicate that behavior reactions in two tasks are corresponding to those two operational principles of taxon system. In terms of the acquisition, deficits were significantly produced by the lesion of the dorsomedial caudate on egocentric task, while the ibotenate lesions did not affect cue learning task (Experiments 1B and 2B). For retention test, the performances in both cue learning and egocentric tasks were impaired by dorsomedial caudate lesion, no such impairment was observed from dorsolateral and posterolateral caudate lesions (Experiments 1C and 2C). In the third and fourth experiments, LiCl devaluation procedure was employed to lower the reward value of the bait in the maze. This manipulation significantly impaired the performance of egocentric task but not that of the cue learning task. These results indicate that the memory representations in the two tasks used in the present study are different. The memory representation in the egocentric task contains the reinforcer, whereas that in the cue learning task is not necessarily relevant to the reinforcer. In conclusion, the guidance and orientation hypotheses can be differentiated as behavioral mechanisms existing in the taxon system of spatial memory. Although the caudate nucleus is critically important for the operation of both hypotheses, the degrees of this brain site to get involved are different. The caudate nucleus participates in the acquisition and retention of orientation hypothesis, but only in the retention of guidance hypothesis. In addition, behavioral performance of the spatial memory using guidance hypothesis is based on forming the association of stimulus and response (S-R), while that using orientation hypothesis is based on forming the association of response and reinforcer (R-S*).
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動態樹狀法-路徑相依選擇權的新評價方法林立人, Lin, Li-Ren Unknown Date (has links)
本文針對路徑相依選擇權(path dependent option)商品,提供一個一般化且有效率評價方法。由於路徑相依選擇權的種類很多,而大部分的美式路徑相依選擇權都沒有封閉解(closed-form),或是封閉解的數學計算過於複雜,而造成評價的困難。此時,透過數值方法可以對路徑相依選擇權定出理論價值。但是選定一個有效率的數值方法是主要的困難,理論上,樹狀模型及蒙地卡羅的數值方法都可以評價路徑相依選擇權,而蒙地卡羅法在評價美式選擇權時較困難,相對而言,使用樹狀模型可以評價美式的選擇權的一個不錯的方法。
自從CRR(Cox, Ross and Rubinstein, 1979)發展二項樹模型(Binomial Tree model)來評價選擇權後,二項樹模型一直被廣泛的應用,此方法基本的概念假設股價的變動為間斷(Discrete)的,且股價呈現上漲或下跌兩種情形,這樣可以容易地來評價歐式及美式的選擇權。之後Boyle(1988)更發展三元樹模型(Trinomial Tree),股價比CRR更多了持平的情形,這樣比CRR多考慮了一種股價行為的模式,實證得知三元樹在穩定性及收斂度上比二項樹表現較佳。
上述二項樹模型及三元樹模型受到節點重合(recombined)的特性,而路徑相依選擇權同一個節點若由不同歷史路徑所產生時,其報酬(payoff)是不同的,報酬可能因為歷史路徑的不同產生很多的情形,所以當路徑相依選擇權的條件越複雜時,要評價一個路徑相依選擇權有其困難性。
本文分別以二項樹模型及三元樹模型來評價路徑相依的選擇權,而為了解決節點可能存在之前的路徑問題,放鬆條件使得節點不再結合一起(non-recombined),如此所有的節點將可以被紀錄,不會有不能評價路徑相依選擇權的問題,但在此情況下會產生另一個問題,節點數隨著切割期數的上昇呈指數成長,使得電腦計算較無效率。
針對路徑選擇權本文提出一個有效率的路徑相依選擇權方法,稱為動態樹狀法(Dynamic Tree Model, DTM),此評價方法建構在風險中立定價(risk-neutral)的理論基礎上。在每一期時間點檢查是否有相同的路徑資訊和標的物現價,若發生路徑資訊和標的物的現價相同且有重複的節點時,可以預期的,這些節點未來長出的子股價樹也會相同,因此不必重複節點,浪費電腦記憶體空間及運算時間,而將此節點予以合併,以達到減少節點個數目的。若遇到不同的路徑資訊或不同標的物現價的節點時,則予以產生。
動態樹狀法將真正需要的節點加以產生,其目的能降低節點數目,改善計算效率,而將此方法廣泛地應用在其他不同的路徑相依選擇權上。而根據不同路徑相依選擇權,我們必須將有用的路徑資訊存在節點上。本文將提出一般化的模型,使用policy設計樣式,以二項樹及三元樹為例,並選擇不同的路徑相依選擇權產品-障礙選擇權、回顧選擇權、亞式選擇權為例,求其理論價值,而實務上通常是間斷(discrete)觀察,我們將討論間斷觀測的情形,比較其觀察點、效率、精確度、節點數目、允許誤差之探討,並提出建議,也能夠廣泛應用在其它路徑相依選擇權上。
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所在、人在:八八水災原住民災民的所在依附感、災難風險知覺、防災準備行為與心理健康 / We are where we are- relationships between place attachment, risk perception, flood preparedness and mental health許乃文, Hsu, Nai Wen Unknown Date (has links)
八八水災於2009年重創南台灣,遷村易安全地而居成為政府防災風險管理的工作重要任務之一,但政策執行時卻遭遇眾多原住民部落不願離家的抗拒,我們由此現象關注到原住民族群特殊的所在依附感,欲透過所在依附感的角度,探討其與風險知覺、防災準備行為、心理健康及心理症狀間的關係。過去文獻對防災準備行為的影響因子並無一致定論,本研究除檢驗災難風險知覺與防災準備行為的關係外,同時認為所在依附感可能對風險知覺與防災準備行為有所影響。由於關切八八原住民災民於災後的心理反應,我們將所在依附感、災難風險知覺、防災準備行為視為災後心理反應的保護因子,檢驗三保護因子分別對生活滿意度、創傷後壓力疾患症狀、憂鬱症狀的影響。本研究於災後約12-15個月,以563名八八災後回鄉居住原住民倖存者為樣本,使用所在依附量表、水災防災準備行為量表、創傷後壓力診斷量表、中文版流行病學研究中心憂鬱量表、TLSA調查中的生活滿意度指標等量表蒐集資料。結果顯示:1. 防災準備方面:生計依附感能夠顯著正向預測防災準備行為、風險可能性與風險擔心度均負向預測防災準備行為,生計依附感同時在風險知覺與防災準備行為間扮演中介變項角色,宗譜傳承及認同向度依附對防災準備行為無顯著預測力;2. 生活滿意度方面:生計依附感對生活滿意度具顯著正向預測力,但此預測力在同時考量防災準備行為時,則下降至不顯著,兩向度風險知覺、防災準備行為均無法顯著預測生活滿意度;3. PTSD症狀方面:三向度所在依附感、兩向度風險覺知、防災準備行為均無法顯著預測PTSD症狀;4. 憂鬱症狀方面:防災準備行為對憂鬱症狀具顯著負向預測力,三向度所在依附感、兩向度風險知覺均對憂鬱症狀不具顯著預測力。 / The aim of this study is to examine relationships between place attachment, risk perception, flood preparedness, mental health, and psychological symptoms after 88 flood disaster in 2009. In particular, investigation focused on three dimensions of place attachment, viz. genealogical, economic, and identity-related. Contextualized scales for place attachment, risk perception, and flood preparedness were developed. Besides, PDS, CES-D, Life Satisfaction Scale were also used in this study. Validity and reliability of the scales were established. Data were collected 12-15 months after the flood from 537 survived and still living in the same homeland aboriginals. Results show, 1. Flood preparedness: economic place attachment predicts flood preparedness positively; two dimensions of risk perception predict flood preparedness negatively, while economic place attachment plays a role as mediator in flood preparedness. 2. Life satisfaction: economic place attachment slightly predicts life satisfaction positively under no consideration to flood preparedness, whereas overall place attachment, risk perception, and flood preparedness have no influence on life satisfaction. 3. PTSD: Neither place attachment, risk perception, nor flood preparedness is related to PTSD. 4. Depression: flood preparedness shows negative impact on depression symptoms; however, place attachment and risk perception do not.
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促進中小企業創新之智慧型激勵故事生成 / Towards motive driven story generation for encouraging SMEs Innovation邱芃瑋, Chiu, Peng Wei Unknown Date (has links)
面臨到現今社會的激烈競爭,服務創新是應付此環境變化的趨勢之一,但大部分台灣的中小企業主並不知道如何將服務創新實踐在他們的企業中。另一方面,大部分中小企業主並不清楚什麼是服務創新,即使知道服務創新可以改善他們的事業,也缺乏實踐的勇氣。因此,為了改善以上的情況,本篇論文的主旨是引用動機理論來建構小客製化的小故事廣告來激勵中小企業主,並讓他們明白服務創新的好處且有勇氣去實踐。為了達到這個目標,我們使用機率擴展有限狀態機(Probabilistic Extended FSM)作為實踐的方法,利用Dramatica的故事元素和十種創新類型的元素並以三幕劇來建構故事架構,在整合中小企業主的相關資料形成完整的激勵故事。從該激勵故事中,中小企業主可以得到一些啟示,改善岌岌可危的業務以實現他們心中的理想。 / Service innovation is one of the tendencies to cope with the environmental change in the current fierce competition, but the most SMEs in Taiwan don’t know how to put service innovation into practice in their business. On the other hand, the most SMEs don’t know what service innovation is; however, even they know service innovation could rescue their poor business; they have no courage to do so. For these reasons which mentioned above, the aim of this research is to reference the motivation theory and try to generate the mini customized advertising-like to stimulate SMEs and let them know the advantage of service innovation and have confidence to do so. In order to achieve this goal, we use Probabilistic Extended FSM as the implementation approach to integrate the private information of our target SMEs with the story framework which is constituted by the three-act Structure including the Dramatica elements and the elements of ten types of innovation. By this kind of stimulating mini customized advertising-like story, the SMEs could get some enlightenment to ameliorate the precarious business to achieve the ideal of their mind.
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跳躍相關風險下狀態轉換模型之選擇權定價:股價指數選擇權實證分析 / Option pricing of a stock index under regime switching model with dependent jump size risks: empirical analysis of the stock index option林琮偉, Lin, Tsung Wei Unknown Date (has links)
本文使用Esscher轉換法推導狀態轉換模型、跳躍獨立風險下狀狀態轉換模型及跳躍相關風險下狀態轉換模型的選擇權定價公式。藉由1999年至2011年道瓊工業指數真實市場資料使用EM演算法估計模型參數並使用概似比檢定得到跳躍相關風險下狀態轉換模型最適合描述報酬率資料。接著進行敏感度分析得知,高波動狀態的機率、報酬率的整體波動度及跳躍頻率三者與買權呈現正相關。最後由市場驗證可知,跳躍相關風險下狀態轉換模型在價平及價外的定價誤差皆是最小,在價平的定價誤差則略高於跳躍獨立風險下狀態轉換模型。 / In this paper, we derive regime switching model, regime switching model with independent jump and regime switching model with dependent jump by Esscher transformation. We use the data from 1999 to 2011 Dow-Jones industrial average index market price to estimate the parameter by EM algorithm. Then we use likelihood ratio test to obtain that regime switching model with dependent jump is the best model to depict return data. Moreover, we do sensitivity analysis and find the result that the probability of the higher volatility state , the overall volatility of rate of return , and the jump frequency are positively correlated with call option value. Finally, we enhance the empirical value of regime switching model with dependent jump by means of calculating the price error.
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厚尾分配在財務與精算領域之應用 / Applications of Heavy-Tailed distributions in finance and actuarial science劉議謙, Liu, I Chien Unknown Date (has links)
本篇論文將厚尾分配(Heavy-Tailed Distribution)應用在財務及保險精算上。本研究主要有三個部分:第一部份是用厚尾分配來重新建構Lee-Carter模型(1992),發現改良後的Lee-Carter模型其配適與預測效果都較準確。第二部分是將厚尾分配建構於具有世代因子(Cohort Factor)的Renshaw and Haberman模型(2006)中,其配適及預測效果皆有顯著改善,此外,針對英格蘭及威爾斯(England and Wales)訂價長壽交換(Longevity Swaps),結果顯示此模型可以支付較少的長壽交換之保費以及避免低估損失準備金。第三部分是財務上的應用,利用Schmidt等人(2006)提出的多元仿射廣義雙曲線分配(Multivariate Affine Generalized Hyperbolic Distributions; MAGH)於Boyle等人(2003)提出的低偏差網狀法(Low Discrepancy Mesh; LDM)來定價多維度的百慕達選擇權。理論上,LDM法的數值會高於Longstaff and Schwartz(2001)提出的最小平方法(Least Square Method; LSM)的數值,而數值分析結果皆一致顯示此性質,藉由此特性,我們可知道多維度之百慕達選擇權的真值落於此範圍之間。 / The thesis focus on the application of heavy-tailed distributions in finance and actuarial science. We provide three applications in this thesis. The first application is that we refine the Lee-Carter model (1992) with heavy-tailed distributions. The results show that the Lee-Carter model with heavy-tailed distributions provide better fitting and prediction. The second application is that we also model the error term of Renshaw and Haberman model (2006) using heavy-tailed distributions and provide an iterative fitting algorithm to generate maximum likelihood estimates under the Cox regression model. Using the RH model with non-Gaussian innovations can pay lower premiums of longevity swaps and avoid the underestimation of loss reserves for England and Wales. The third application is that we use multivariate affine generalized hyperbolic (MAGH) distributions introduced by Schmidt et al. (2006) and low discrepancy mesh (LDM) method introduced by Boyle et al. (2003), to show how to price multidimensional Bermudan derivatives. In addition, the LDM estimates are higher than the corresponding estimates from the Least Square Method (LSM) of Longstaff and Schwartz (2001). This is consistent with the property that the LDM estimate is high bias while the LSM estimate is low bias. This property also ensures that the true option value will lie between these two bounds.
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工程契約變更之爭議問題陳玉潔 Unknown Date (has links)
工程契約變更在工程進行中極為常見,其亦為常引起工程爭議事由之一。惟我國民法承攬一節,係對於具有完成一定工作特徵之契約而設,並未針對工程契約之特性與特殊問題設置規範,因此,在工程契約中解釋與適用法律時,常出現困難與見解不一之情形,定作人與承攬人權利義務關係處於不明確之狀態。以我國法角度探討工程變更爭議中當事人權利義務關係,應有必要。
本文將工程契約變更之爭議略分為三部分:第一部分是在何種情形下定作人應辦理工程契約變更?此問題涉及工程契約變更之原因以及契約工作範圍。契約之工作範圍如何以契約解釋加以認定?工地狀況與契約工作範圍之關係為何?工作範圍的改變應如何認定?此等將於本文第三章討論。
第二部分是當定作人辦理工程契約變更時,雙方權利義務為何?於此之下將討論定作人除有變更之權利外,是否有變更之義務?承攬人除得請求報酬外,是否有通知、繼續施工及照顧維持工地之義務?其次,定作人應如何辦理工程契約變更?於此將討論工程契約變更之程序、主體、時間、方式、應遵循之法令。定作人辦理工程契約變更限制為何?本文略整理出幾項限制:1.針對工作指示變更2.契約通常範圍之限制(契約同一性之限制)3.減少工作之限制4.政府採購法之限制5.建築法規之限制。最後,承攬人於定作人辦理工程契約變更時,是否得請求調整報酬及展延工期?此等問題將於第四章討論。
第三部分置於第五章之下,當定作人未辦理工程契約變更,但定作人其他指示或行為造成承攬人施作契約外工作時,承攬人得否請求依契約中工程變更約定調整報酬及展延工期?此問題涉及所謂「擬制變更」理論,本文認為不應援用擬制變更理論解決爭議,而應將定作人其他指示或行為造成承攬人施作契約外工作之情形區別以下類型討論:1.雙方就契約之約定解釋歧異2.有瑕疵之契約規範及業主未揭露資訊3.趕工4.業主干擾或在履約過程未能協力配合,以此為主軸分析當事人於我國法下之法律關係。反之,如不認為承攬人施作契約外工作時係因定作人其他指示或行為所造成,乃是承攬人自行施做時,則產生承攬人得否主張無因管理或不當得利之問題?最後,將一併於第五章討論實務中常見之漏項與實做數量爭議,釐清與工程契約變更之關係。
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大腦度巴胺系統在大鼠操作式制約行為中所扮演的角色:以時間為主 / The Role of Brain Dopamine Systems on Operant Conditioned Behavior in the Rat: From Temporal Perspective鄭瑞光 Unknown Date (has links)
周邊注射安非它命能夠影響動物受試在表現與時間知覺有關的操作式制約行為作業,歷來被研究者認為是大腦多巴胺神經系統與動物時間知覺系統有關的主要證據之一。本研究所共同採用的研究方法為先注射多巴胺受體專屬拮抗劑再於大鼠受試周邊腹腔注射安非它命的方式探討安非它命影響大鼠時間知覺的大腦機制為何。實驗一利用區辨性增強低頻反應作業觀察周邊注射多巴胺受體專屬拮抗劑何者可以反制周邊安非它命對此作業的影響效果,結果發現多巴胺D1受體拮抗劑SCH23390與D2受體拮抗劑raclopride均可反制周邊安非它命的效果。實驗二同樣利用區辨性增強低頻反應作業,但是將SCH23390與raclopride分別注入海馬迴、背側中區紋狀體、腹側側邊紋狀體、依核、內側前額葉皮質以及腹側頂蓋區等六個部位,觀察何種多巴胺受體拮抗劑可在那些大腦部位產生反制周邊安非它命的效果。結果發現SCH23390可在海馬迴、依核、內側前額葉皮質以及腹側頂蓋區等四個部位產生反制周邊安非它命的效果,而raclopride可在腹側側邊紋狀體與內側前額葉皮質兩個部位產生同樣的反制效果。實驗三利用高峰時距作業觀察SCH23390在海馬迴與內側前額葉皮質是否能反制周邊安非它命對此作業的影響效果,結果發現SCH23390僅在海馬迴會影響大鼠受試的正常表現,特別是在與周邊安非它命同時注射的時候。綜合以上結果顯示,周邊注射安非它命能夠使大鼠受試在區辨性增強低頻反應作業當中表現出時間知覺變快的傾向,這個效果需要同時透過大腦內的海馬迴、依核、內側前額葉皮質以及腹側頂蓋區的多巴胺D1類受體和腹側側邊紋狀體與內側前額葉皮質的多巴胺D2類受體。 / The central dopaminergic system has been hypothesized to play a role in time perception based on the results that peripheral injections of d-amphetamine alter the responses in time-related operant conditioned behavioral tasks. The present study investigated the effect by injecting specific dopamine receptor antagonists before peripheral d-amphetamine injections in rats. Data from Experiment I showed that both peripheral the dopamine receptor D1 antagonist SCH23390 and D2 antagonist raclopride could attenuate the response alteration on differential reinforcement of low-rates responding task induced by peripheral d-amphetamine. By using the DRL task, Experiment 2 employed the microjeciton technique to determine the neural substrates for the DA receptor antagonist to attenuate the effect of peripheral d-amphetamine. The infusion sites for DA receptor antagonist were the hippocampus, the dorsomedial striatum, the ventrolateral striatum, the nucleus accumbens, the medial prefrontal cortex, and the ventral tegme ntal area. The results showed that SCH23390 infused into the hippocampus, the nucleus accumbens, the medial prefrontal cortex, the ventral tegmental area could attenuate the effect induced by peripheral d-amphetamine, and such attenuation effects were also observed for raclopride infused into the ventrolateral striatum, the medial prefrontal cortex. Experiment 3 tried to confirm the results of Experiment 2 by microinjecting SCH23390 in hippocampus and medial prefrontal cortex under peak-interval task. Only SCH23390 in the hippocampus altered the subject's normal performance in this task especially when combined with peripheral injection of d-amphetamine. In conclusion, that the response alteration on the DRL task induced by peripheral injection ofd-amphetamine suggests the subject's timing perception being accelerated. These effects of d-amphetamine were mediated by simultaneous activation of multiple dopamine receptor subtypes including D1 receptors located in the hippocampus, nucleus accumbens, medial pref rontal cortex, ventral tegmental area, as well as D2 receptors located in the ventrolateral striatum, medial prefrontal cortex.
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以特徵向量法解條件分配相容性問題 / Solving compatibility issues of conditional distributions by eigenvector approach顧仲航, Ku, Chung Hang Unknown Date (has links)
給定兩個隨機變數的條件機率矩陣A和B,相容性問題的主要課題包
含:(一)如何判斷他們是否相容?若相容,則如何檢驗聯合分配的唯一性
或找出所有的聯合分配;(二)若不相容,則如何訂定測量不相容程度的方
法並找出最近似聯合分配。目前的文獻資料有幾種解決問題的途徑,例
如Arnold and Press (1989)的比值矩陣法、Song et al. (2010)的不可約
化對角塊狀矩陣法及Arnold et al. (2002)的數學規劃法等,經由這些方法
的啟發,本文發展出創新的特徵向量法來處理前述的相容性課題。
當A和B相容時,我們觀察到邊際分配分別是AB′和B′A對應特徵值1的
特徵向量。因此,在以邊際分配檢驗相容性時,特徵向量法僅需檢驗滿足
特徵向量條件的邊際分配,大幅度減少了檢驗的工作量。利用線性代數中
的Perron定理和不可約化對角塊狀矩陣的概念,特徵向量法可圓滿處理相
容性問題(一)的部份。
當A和B不相容時,特徵向量法也可衍生出一個測量不相容程度的簡單
方法。由於不同的測量方法可得到不同的最近似聯合分配,為了比較其優
劣,本文中提出了以條件分配的偏差加上邊際分配的偏差作為評量最近似
聯合分配的標準。特徵向量法除了可推導出最近似聯合分配的公式解外,
經過例子的驗證,在此評量標準下特徵向量法也獲得比其他測量法更佳的
最近似聯合分配。由是,特徵向量法也可用在處理相容性問題(二)的部份。
最後,將特徵向量法實際應用在兩人零和有限賽局問題上。作業研究的
解法是將雙方採取何種策略視為獨立,但是我們認為雙方可利用償付值表
所提供的資訊作為決策的依據,並將雙方的策略寫成兩個條件機率矩陣,
則賽局問題被轉換為相容性問題。我們可用廣義相容的概念對賽局的解進
行分析,並在各種測度下討論賽局的解及雙方的最佳策略。 / Given two conditional probability matrices A and B of two random
variables, the issues of the compatibility include: (a) how to determine
whether they are compatible? If compatible, how to check the uniqueness
of the joint distribution or find all possible joint distributions; (b)
if incompatible, how to measure how far they are from compatibility
and find the most nearly compatible joint distribution. There are
several approaches to solve these problems, such as the ratio matrix
method(Arnold and Press, 1989), the IBD matrix method(Song et
al., 2010) and the mathematical programming method(Arnold et al.,
2002). Inspired by these methods, the thesis develops the eigenvector
approach to deal with the compatibility issues.
When A and B are compatible, it is observed that the marginal distributions
are eigenvectors of AB′ and B′A corresponding to 1, respectively.
While checking compatibility by the marginal distributions, the
eigenvector approach only checks the marginal distributions which are
eigenvectors of AB′ and B′A. It significantly reduces the workload.
By using Perron theorem and the concept of the IBD matrix, the part
(a) of compatibility issues can be dealt with the eigenvector approach.
When A and B are incompatible, a simple way to measure the degree
of incompatibility can be derived from the eigenvector approach.
In order to compare the most nearly compatible joint distributions
given by different measures, the thesis proposes the deviation of the
conditional distributions plus the deviation of the marginal distributions
as the most nearly compatible joint distribution assessment standard.
The eigenvector approach not only derives formula for the most
nearly compatible distribution, but also provides better joint distribution
than those given by the other measures through the validations
under this standard. The part (b) of compatibility issues can also be
dealt with the eigenvector approach.
Finally, the eigenvector approach is used in solving game problems.
In operations research, strategies adopted by both players are assumed
to be independent. However, this independent assumption may not
be appropriate, since both players can make decisions through the
information provided by the payoffs for the game. Let strategies of
both players form two conditional probability matrices, then the game
problems can be converted into compatibility issues. We can use the
concept of generalized compatibility to analyze game solutions and
discuss the best strategies for both players in a variety of measurements.
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