在我國股市中，自營商、外資與投信都被歸類為，具備優越知識之三大專業投資法人；所謂的優越知識應是代表該投資法人蒐集、解釋與分析攸關資訊的專業知識與經驗，而其中的會計資訊就是投資人最重要的基本資訊來源之一。故本研究預期會計資訊鷹會對自營商的投資策略產生影響，也就是說，自營商在進行投資策略時，會參考會計資訊。 本研究採用T檢定與迴歸分析法，來探討從民國八十四年七月一日至八十五年六月三十日止之一年間，自營商投資策略與會計資訊的關係，共採用349家樣本公司的18148筆自營商買（賣）超週資料。本研究中所指的會計資訊是定義為上市公司季報、半年報、年報中的每股盈餘，據以算出之季盈餘成長率；至於本研究中之自營商的投資策略則為「每週自營商買進賣出較多表」中，以買進減去賣出所得到的買（賣）超，據以算出其各季之平均成長率。 經實證分析，本研究所獲致的結論茲彙述如下： 一、相對於去年同一季而言，若個股本季的季盈餘成長率為正，並未如預期一般：自營商買超的成長率為正，或賣超的成長率為負，亦即買（賣）超的成長率並未增加。這可能是因為自營商在進行其投資策略時，季盈餘成長率資訊可能是一個參考資訊，但是並不是一個具有關鍵性的參考資訊，或者是要和其他資訊一起考量才有其重要性。 二、相對於去年同一季而言，若個股本季的季盈餘成長率為負，並未如預期一般：自營商買超的成長率為負，或賣超的成長率為正，亦即買（賣）超的成長率並未減少。同上之推論，這可能是因為自營商在進行其投資策略時，季盈餘成長率資訊可能只是一個參考資訊，而不是一個具有關鍵性的參考資訊，或者是要和其他資訊一起考量才有其重要性的緣故。 三、相同地，自營商買（賣）超的成長率與季盈餘成長率的幅度並未如預期地呈現正相關，也就是說季盈餘成長率為正，且成長率愈高者，其買（賣）超成長率並不會愈高。此結果更加證明季盈餘成長率並不是自營商在進行投資策略時的關鍵參考指標，或者是要合併其他資訊一同考量才能顯示出其重要性。 四、同（三）之結論，自營商買（賣）超的成長率與季盈餘成長率的幅度並未如預期地呈現正相關，也就是說季盈餘成長率為負，且成長率愈小者，其買（賣）超成長率並不會愈低。此結果更加證明季盈餘成長率並不是自營商在進行投資策略時的關鍵參考指標，或者是要合併其他資訊一同考量才能顯示出其重要性。 五、在買（賣）超成長率為正時，若季盈餘成長率為正，相較於季盈餘成長率為負的情況下，自營商的買超成長率會較小，或賣超成長率會較大，也就是說：買（賣）超成長率會比較小。此結果和預期正好相反。這可能是因為自營商面對好消息時，會稍有遲疑，未敢為上反應並買進較多或賣出較少股票，即所謂「季節延遲」效應，因此其買（賣）超成長率反而小於面對壞消息時的反應。 六、在買（賣）超成長率為負時，若季盈餘成長率為負，相較於季盈餘成長率為正的情況下，自營商的買超成長率會較小，或賣超成長率會較大，也就是說：買（賣）超成長率會比較小。此結果和預期相符。

在耐延遲網路(Delay Tolerant Network)中，因節點之間的高移動性、連接的不確定性環境嚴苛限制，採用Store-And-Forward 訊息傳輸的模式提供一個可接受的網路表現。常見的路由協定可分為機會路由、基於預測的路由以及調度路由，然而這些路由協定使用在市區環境中，有些許不足的地方，因此我們提出適用在市區封包轉發策略。 我們提出的以公車亭為基礎之耐延遲車載網路封包轉發策略，是在市區環境中建立一個以公車亭為基礎的資料傳送架構，包含汽車、公車、公車站、公車轉運站四種節點。我們建立節點與節點相遇時資料傳送規則，例如汽車與汽車相遇、汽車與公車相遇、公車與公車站相遇、公車與公車轉運站相遇、公車轉運站與公車相遇、公車站與汽車相遇、汽車與目的地相遇時各自有不同的資料傳送判斷與限制。 實驗結果也證明所提出的演算法，除了可以有效地減少延遲傳送時間並提高訊息成功傳送率，及在各節點有限的緩衝區大小下，我們的封包轉發策略有著最突出的效能。 / In Delay Tolerant Networks (DTNs), there does not exist an end-to-end path due to intermittent connectivity and high node mobility. Messages are stored for a period of time at network nodes and are conveyed hop-by-hop to the destination. The current DTN routing protocols can be summarized into three categories: opportunistic, prediction-based and scheduling protocols. However, these routing protocols have some deficiencies and are not specifically focused on the urban areas. Based on the characteristics of urban areas, we proposed a kiosk based packet forwarding strategy for vehicular delay tolerant networks. We established the rules of data transmission when one node contacts other nodes. More specifically, Car-to-Car, Car-to-Bus, Bus-to-Bus stop, Bus-to-Bus transfer station, Bus transfer station-to-Bus, Bus stop-to-Car ,Car-to-Destination contacts, have different judgments and restrictions for data forwarding. The simulation results demonstrate that we proposed packet forwarding strategy would reduce the delivery delay, and improve the successful delivery rate. Especially with limited buffer and little overhead, our proposed strategy has the most prominent performance.

許多國家正面臨因嚴重的交通壅塞所帶來龐大的經濟損失，同樣在台灣也面臨相同問題，根本解決之道就是找出壅塞路段，並即時地告知車輛駕駛以迴避此路段。因此如何有效率地偵測出壅塞路段，是當前重要的議題。以往大多透過長期所累積的統計數據，針對各路段收集行駛於該路段所有車輛的平均速度，來獲得該路段的交通狀況，但卻無法立即反應即時路況。 因此我們提出以耐延遲車載網路方式，收集路況資訊與彙整旅途時程，透過具有全球定位系統(GPS)以及無線網路的車輛來進行路況交通資訊的收整與交換。再透過本研究所提出路況交通覺知路由協定(RTARP)，以One-Hop Controlled Flooding的傳輸方式在節點與節點相遇時進行路況資訊的傳送，進而交換節點彼此間各自所存放各路段的路況資訊。 模擬實驗結果證明我們所提出的路由協定在路況交通資訊交換中，有效地減少網路傳輸負載、提高訊息送達成功率以及路況交通資訊(RTI)正確率。 / Many countries are concerning about the huge economic losses caused by the critical traffic congestion. We have the same problem in Taiwan. The solutions lie in finding the road section with traffic congestion first and informing drivers to avoid that section. But how to detect the road section with traffic congestion effectively is the most important issue of this research. Conventionally, the real-time road traffic is mostly predicted by long-term accumulated statistics calculated by the collection of the average speed of cars on the same road section. But this way can’t provide the real-time road traffic immediately. Based on vehicles with GPS and the capability of WiFi, we proposed gathering road traffic information and consolidating travel time estimation using vehicular delay tolerant networks. We also proposed the Road Traffic Awareness Routing Protocol (RTARP) to exchange the road traffic information preserved individually by One-Hop Controlled Flooding during nodes’ encounter. The results of simulations prove the routing protocol we proposed can effectively reduce the transmission overhead, improve the delivery ratio and the accuracy of the road traffic information.

近年來通訊網路的進步與寬頻網路的發展，使得更多新型的網路服務迅速應運而生，對網路服務的品質(QoS)也更加要求。眾多新興的應用服務中，即時性的應用服務(real-time traffic)，像是Voice over IP (VoIP)以及video on demand (VoD)，對於封包的傳遞延遲時間(delay time)以及抖動(jitter)具有嚴格的要求，router在處理即時性封包時，並非僅將封包快速送出即可，而須在一定的延遲時間內送出。本研究在BBQ﹙Budget-Base QoS﹚的架構下，發展一套簡單而有效的方法，在封包所經過的每一個router時，根據其緊急程度、服務等級及網路處理能力賦予合適的profit function，再對封包重新排程以獲得最大的profit，期望減小在接收端的jitter絕對值總和，進而增進網路的效能。在此我們設計了四種profit function配合Greedy演算法在兩種不同的router架構上調整封包傳送順序，並利用網路模擬工具NS2在即時性訊務分為單一服務等級及雙服務等級的情況下評估我們方法的效能，證明我們的方法較既有的方法更可以有效控制jitter，且能對不同的服務等級做適當的差異化處理以提高整體服務滿意度。 / With fast growth of Internet traffic and applications, real-time streaming applications have attracted significant attention in the current Internet society. Novel real-time Internet applications such as Voice over IP (VoIP) and video on demand (VoD), have stringent delay and jitter requirements. Under these requirements a router not only have to forward real-time packet as fast as possible, it also have to accomplish the job within a time bound. Our research is based on BBQ﹙Budget-Based QoS﹚management architecture. In order to minimize the jitter of real-time services, we propose a new jitter control mechanism that uses per-hop packet scheduling. Four profit function are designed to represent different scheduling preferences. When a packet gets into a router, the router will assign a profit function based on its timeness and the class of service. The scheduler will re-schedule their order in output queue aiming to maximize total profit. Finally we evaluate our proposed mechanism by NS2 simulator in two situations, single real-time service class and two real-time service classes. Simulation results show that by using our approach the performance is better than other approaches. And we investigate the performance of the combination of profit function in handling multiple classes of service.

DTN(Delay Tolerant Networks)是一種缺乏網路基礎設備的網路架構，在這類的網路架構下，無線節點之間的通訊連線並非同時存在，而是間歇式建立的。因為節點的移動、或是裝置省電模式運作與環境因素的影響，造成連線可能不定時的失效。有不保證連線特性的網路，在DTN網路中節點間相遇的機會很少，節點間利用 Store-Carry-Forward 的方式傳遞訊息，且有相當長的傳遞延遲(Propagation Delay)。在這樣的網路特性下，傳統的文獻中，都是假設所有節點都會幫忙傳遞。但不幸的，在現實生活中有自私節點(Selfish Nodes)的存在，因自己本身設備資源有限，如電力資源、網路資源...等，節點不願意幫忙傳送訊息，這些自私節點的存在，會對DTN網路架構造成破壞，導致無法傳送訊息到目的地。為了解決自私節點的問題，我們提出了MTBIS(Mobile Trusted Bank of Incentive Strategies)，當發送節點(Source Node)要求傳送訊息時，給予回饋給幫忙轉傳訊息的節點，來鼓勵節點間互相幫忙傳送訊息，我們稱這些回饋為Incentive Credit。而節點也可利用Incentive Credit來要求別的節點幫忙轉傳訊息。另外也加入SI(Social Incentive)機制，與DGT(Dynamic Grudger Threshold) ，吸引自私節點願意幫忙轉傳訊息，改進了 MTBIS 在自私節點環境下的不足， 利用經濟學的角度來解決節點運用Credit的問題，借此提高訊息的傳遞率(Delivery Ratio)。 本篇研究也注重於自私節點的模擬，利用四種不同特性的節點： Sucker(傻瓜)、Cheater (騙子)、Grudger(小氣鬼)、Ecci(投機者)， 這些自私節點會照成DTN在設計上無法使用，甚至降低訊息的傳達率，因此我們模擬了這些自私節點的行為，並且使用我們所提出的獎勵機制，來解決這些自私節點的問題，實驗結果也證明，Grudger可以有效的抑制自私節點對效能大幅降低的問題，與傳統的演算法相較，效能高出34%。 / DTN (Delay Tolerant Networks) is a network structure without need to use any infrastructure. In DTNs, wireless connections between nodes do not always exist, i.e., nodes are connected intermittently. Due to the mobility, power issues, or surrounding environment of nodes, connections between nodes may be disruptive occasionally or randomly. In a DTN, nodes usually transfer the message to the encountering nodes. By this way, the messages are stored, carried, and forwarded to the next nodes, possibly the destination. However, in reality, nodes may not be willing to help each other for the message forwarding. More specifically, there are “Selfish nodes” which refuse to forward messages due to issues such as energy and network bandwidth. Thus it will prevent messages from being forwarded to its destination. In order to solve the problem of message forwarding failure caused by selfish nodes, we proposed an Incentive Strategy called “MTBIS (Mobile Trusted Bank and Incentive Strategies)”. We construct a rewarding scheme called “Incentive Credit” for nodes who forward the messages for the source node. In addition, to increase the intention of the selfish nodes for forwarding messages, we add two more mechanism called SI(Social Incentive) and DGT(Dynamic Grudger Threshold). The DGT uses credits to solve selfish node problems from an economics point of view to enhance MTBIS to work with existence of selfish nodes. In this thesis, we emphasis on the simulation of the behaviors of selfish nodes, using four different types of nodes: the “Sucker”, the “Cheater”, the “Grudger”, and the “Ecci”. These selfish nodes will decrease the success rate of message forwarding, and even make the DTN unusable. We simulated the behaviors of these selfish nodes, using the rewarding scheme we proposed. From the results of our experiment, we see that the Grudger can effectively deal with performance issues caused by selfish nodes, and the system can gain 34% in performance compared to the traditional algorithms.

本研究主旨在於探討學術期刊普遍禁止一稿多投的現象與其成因。文章中將使用考慮出版者以及學術投稿者的兩階段模型來刻劃投稿、審查，以及投稿規則決策的過程。 初步模型將呈現當投稿者無明顯時間偏好以及各期刊審稿延遲時間一致時，一稿一投或是一稿多投規則對於整體學術產業而言並無差異。其後本文第四章將導入差異審稿延遲所帶來的影響並得出擁有較高聲望的期刊為避免在一稿多投制度下次級期刊利用較快的審查速度奪取較高品質的文章因而將不願意開放一稿多投的結論。 本研究後部分章節將分析各投稿規則對於整體產業福利水準之影響並得到以下結論。一稿一投制度不見得會為整體產業帶來福利增進，但由於投稿者與出版者之間利益不一致性的存在終將難以使得一稿多投成為最後的均衡投稿規則。 / This paper attempts to explore “why the journals in most academic fields like economics refuse to accept Multiple-submission (or simultaneous submission).” In this study, we use a two-stage model involving publishers and academic authors to illustrate the process of submitting, reviewing, and the submission policy determining. The first model shows an indifference result for the whole academic industry to adopt a Sole-submission or a Multiple-submission rule when authors’ utility is time-irrelevant and the reviewing delays of both journals are identical. We latter introduce the effect of differentiated refereeing delay of journals on the authors’ submission behavior in chapter 4 and show that a journal with higher prestige will refuse to adopt multiple submission rule to avoid the possibility that a faster reviewing process may give the less prestigious journal ability to “steal” high quality papers from the more prestigious one under multiple-submission. The welfare is further studied in the later sections. We calculate the overall welfare of the industry and find that even thought the current sole-submission system is not necessarily welfare superior than multiple-submission, it seems that the rigidity of the submission rule is hard to be removed due to the conflicting interests between authors and publishers.

本研究先將延遲策略在全球運籌管理上應用作一完整介紹，再對台灣的電子業進行實証研究，主要目的在探討：1.廠商所從事的延遲策略有那些態樣；2.產品特性對這些延遲策略態樣影嚮；3.消費者需求對這些延遲態樣影嚮；4.生產狀況對這些延遲策略態樣影嚮。 在對台灣電子廠商發放問卷後，從事統計分析，本研究先以因素分析探討目前台灣廠商所從事延遲策略的態樣，進而將這些態樣和公司基本資料、產品特性、消費者特性和生產狀況作相關分析，找出其中關係。而本研究之主要發現如下： 1.廠商從事延遲策略有以下幾種態樣：型態延遲（包裝、生產、標籤、組裝四種，其中包裝和組裝又分成二類），時間延遲，和行銷延遲。廠商亦從事功能性加速。 2.消費者重視時間因素和產品功能，高價值產品、高技術產品、合作產銷、產品有季節性需求和快速生產等因素會造成廠商從事不同的延遲策略。 因此依據研究結果，建議廠商可參考不同的延遲態樣，同時並思考自己的客戶需求、產品特性和生產等因素，在全球運籌管理架構下找出可能的延遲行為，將有助於成本減少和風險的降低。

耐延遲網路(Delay Tolerant Networks)上的路由協定可以區分為兩大類:flooding-based protocols 跟forwarding-based protocols。網路編碼(Network Coding)是一種編碼技術可以提高訊息傳輸的可靠度；並且運作時不需要知道整體網路的拓樸資訊。 我們提出的演算法結合了flooding-based protocols 跟forwarding-based protocol特性，最主要的概念是讓訊息不是被傳送給每一個節點，而是傳送給朝向目的地或是接近目的地的節點。當節點相遇時，我們的方法會利用節點的路徑、移動方向與速度去預測到達目的地的機率。同時我們利用網路編碼的技巧傳送編碼後的資料來代替訊息的片段，來避免重複傳送多餘的訊息；並讓通訊更加可靠。根據實驗模擬的結果，我們的機制有較好的效能，特別是在頻寬的使用上。 / The routing protocols of delay tolerant networks could be divided in two categories: flooding-based protocols and forwarding-based protocols. Network coding is an encoding technique that could make data transmission more reliable. It operates without the needed of information about the network topology. We proposed a routing protocol integrating the characteristic of flooding-based protocol and forwarding-based protocol. The main idea of our protocol is to let message would not be flooded to every node but to the nodes moving toward or moving closer to destination. When nodes contact with each other, our approach will use the path of node, node’s moving direction and its velocity to estimate the probability to reach the destination of message. At the same time, we exploit network coding to transmit coded block instead of message fragment in order to avoid sending redundant replication, make data transmit more reliable and more robust to packet losses or delays. From the result of simulation, we could see that our protocol have a higher performance especially in the bandwidth consumption compared to other protocols.

本研究在減低Wimax mesh mode環境中media access階段會造成的delay現象。我們發現當subscriber station (SS)訊務繁忙時，競爭transmission opportunity (TO)以及3-way handshake的過程容易失敗，造成傳輸效率降低，封包的delay也會增加。同時我們也發現封包的延遲還來自minislot的不良配置。因為原始的Wimax mesh mode對於minislot的配置會造成預約過晚的問題，當預約時間被延長，資料就必須無條件的增加等待時間，因此我們將針對這些問題進行改善，降低在訊務繁忙的狀況下，傳輸效率低落的問題。 我們使用兩種方式來改善上述的問題，其一是由Bayer [4]所提出的動態調整holdoff指數(dynamic holdoff exponent)的方式，藉由調整holdoff指數的大小來縮短holdoff時間，以縮短傳輸延遲；另外，我們也提出一個以節點的臨接區域為配置基準(Neighborhood-Based Minislot Allocation, NBMA) 的方法，透過與其相鄰的節點交換訊息，優化minislot的配置。我們用這兩種方式減少IEEE 802.16中媒體存取階段所造成的傳輸延遲。 實驗結果顯示，在網路負載較輕的情況下，NBMA可以有效的將delay降低為原來的七分之一，改善幅度將近85%，抖動率(jitter)的部分亦有20%的改善，並略為提高傳輸效能8%左右；而當網路負載較重時，delay的改善程度仍有40%左右，jitter部分改善了12%，傳輸效能亦有6%的改善。證明了我們的方法確實可行，並且在改善delay方面有顯著的效果。 / IEEE 802.16 mesh network is a new environment of wireless network. It was designed as a self-organized, distributed scheduling, and multi-hop network. However, it is not robust enough to handle a heavy loading environment for lacking of QoS support. Our research is trying to reduce its media access delay, which comes from both TO (transmission opportunity) competition and improper minislot allocation. TO competition will extend the MSH-DSCH (mesh distributed scheduling) interval and slow down the exchanging speed of control message. Improper minislot allocation comes from the distributed scheduling of minislot. When a subscriber station (SS) allocates too much minislot for low-level traffic, it will defer the allocation of other neighbors’ high-level traffic. We use Bayer’s [4] dynamic exponent to reduce holdoff time of SS, and speed up the exchange of control message. On the other hand, we design an “importance factor” (IM-factor) to score the importance of request. Through the exchange of IM-factor, SS and its neighbors will produce a threshold of IM-factor to filter the unimportant requests, and prevent minislot from being assigned too late. In our experiments, the proposed methods can reduce 85% delay and 20% jitter, and increase bandwidth utility by 7%. It shows that our method in reducing transmission delay is pratical and effective.

在DTN(Delay Tolerant Networks)這類的網路架構下，無線節點之 間的通訊連線是採非連續性建立的。DTN 路由協定中, 決定中繼節點 方式大致可以分成兩類:依地理位置考量的路由協定（Geographic Routing Protocal）和依社交模式考量的路由協定（Social-based Routing Portocal）。 由於人與人間的互動是透過社交關係, 但是真實的資訊傳遞又須 仰賴當時的地理位置。因此我們提出的演算法將網路拓墣分成社交層與地理層, 在社交層中利用Social Ally Selection Algorithm 挑選出合適的社交盟友(Social Ally)。在地理層中利用Geographic Messenger Forwarding Algorithm 挑選合適的節點將訊息傳送給朝向目的地或是社交中繼站的節點。根據實驗模擬結果, 我們的路由協定能有較佳的傳遞成功率, 並降低了延遲時間。 / Delay Tolerant networks (DTN) may lack continuous network connectivity. Most of these DTN routing protocol, which attempt to make better routing decision, could be divided in two categories: Geographic routing protocols and Social-based routing protocols. Due to the interaction between people through social behaviors and message transmissions rely on geographic position information, we proposed a routing protocol which network topology is divided into two sub layers: social layer and geographic layer. In social layer, we propose a Social Ally Selection Algorithm to decide social allies that are controlled to improve delivery performance. In geographic layer, we propose a Geographic Messenger Forwarding Algorithm to transmit message to the nodes moving toward to social ally or destination. According to the simulation results, we could show that our routing protocol have higher delivery ratio and lower delay latency compare to other protocols.