台灣留學生出席國際會議補助

An Approach to Assessing Freeway Lane Management Hot Spots

2009-07-06T14:44:00.001-07:00

論文發表人: 鍾智林 (加州大學爾灣分校土木所博士班)

http://www.trb.org/meeting/2009/default.asp

本論文針對高乘載/收費車道與一般車道的競合關係，探討如何將車道剩餘容量即時且正確地供不同車道使用。高乘載/收費車道與一般車道可歸納成三種互動關係，包括『維持現況』、『需車道管理』、『超出車道管理範圍』。當兩類車道其中之一產生擁擠，而另一類尚有剩餘容量時，即產生車道管理熱點。本研究於24英里長加州高速公路案例中，以定性及非定性方法辨識出四處主要與三處次要車道管理熱點，四處主要熱點占研究路段時空集合的8.4%。本研究方法亦可準確預測車道管理熱點。文末提出車道管理熱點之因應策略並概估其成效。本方法尤適於部分進出管制之高乘載/收費車道。

This paper focuses on the tradeoff relationship between HOV/HOT lanes and general-purpose (GP) lanes that compete for limited road space. The basic idea is about sharing the excess lane capacity with each other on a timely and accurate basis. Potential conditions between these two types of lanes are categorized as "do nothing", "lane management", and "more than lane management". The "lane management" condition recognizes the extent and duration of a hot spot defined as low-utilized HOV/HOT lanes with congested general-purpose lanes, or vise versa. Four major and three minor lane management hot spots are deterministically and stochastically captured along a 24-mile freeway stretch in California. The major ones account for 8.3 percent of the total time-space set. The approach can also be applied to predict upcoming hot spots and acquires satisfying accuracy. Finally, strategies are proposed to prevent the hot spots and the effects of lane management are briefly estimated. The application of this approach is especially useful for HOV/HOT lanes of limited access points that prohibit vehicles of arbitrary shift between HOV/HOT and GP lanes.

2009 Classical Marimba League Marimba Artist Competition Winners Concert: The Performance of Selected Marimba Solo Works- “Cameleon,” “Variations on Japanese Children’s Song” and “Dr. Gradus ad Parnassum.”

2009-07-06T14:41:00.001-07:00

論文發表人：陳儀嘉（亞利桑那州立大學音樂系音樂演奏博士班）

http://www.classicalmarimba.com/

古典木琴聯盟之宗旨為激勵現代作曲家，融合其獨特作曲技巧，並以過去各時期的音樂風格為骨幹，來創作不同編制的木琴曲。古典木琴聯盟亦舉辦年度國際木琴大賽，提供木琴演奏者展露其長的機會。此次演出之樂曲為當代重要木琴獨奏曲「變色龍」，「日本兒歌變奏」，以及改編作品「兒童天地」鋼琴組曲中的「帕納森博士」。「變色龍」為具有法國以及爵士音樂影響的木琴獨奏樂曲。此曲為三段式（ABA）曲式加上尾奏。A段由流暢且多采的樂句所展開並貫串；B段則轉換為較快的速度，樂曲的第二主題在此由強烈節奏性的樂段所帶出，快速的節奏以及重音塑造了此段活躍且有力的特質。B段在尾處以漸弱及漸慢緩和強烈的樂段，並銜接回如歌般的A段，由溫和深遠的尾奏結尾。「日本兒歌變奏」由三個主要段落組成。第一段由不同音量、樂句長度的頑固低音以及主要樂思所展開，第二段則呈現了數段裝飾奏般的樂段。音量的對比、速度的變化、漸快、漸慢以及速度自由的高度使用使演奏者得以較為自由的表現對裝飾奏樂段的獨特詮釋。最後一個段落不但涵蓋快速的音量（dynamic）、音色（timbre）以及音域（register）的轉換，並且運用樂曲的主要樂思以及素材，建立樂曲之高潮以及輝煌有力的結尾。「帕納森博士」為一短小卻深奧豐富的樂曲，演奏者須運用高度的四隻琴槌控制技巧以詮釋此曲。其中快速的十六分音符樂段需要迅速且準確的單手音程變換，以及非常精確平均的雙擊（double stroke）來呈現流暢的樂句。演奏者亦須運用跨越棒法（cross sticking）來呈現十六分音符琶音樂句的重音。而樂曲中氣氛的變換，須要藉由精細敏銳的觸鍵（touching）來呈現多變的音色以及各段落的音樂特質。此次演出的三首樂曲風格相異，但對於演奏者在音樂的處理以及技巧的運用上，皆有著相當程度的挑戰。

Classical Marimba League (CML) is an organization to establish a legacy of marimba music that honors the notable styles of the past within the creative expression of emerging composers from all over the world. CML holds annual International Marimba Artist Competition to provide a venue for marimba performers to showcase their talent. The pieces performed in the competition are "Cameleon" and "Variations on Japanese Children's Songs" from standard marimba solo literature and a transcription "Dr. Gradus ad Parnassum" from piano solo suite "Children's Corner." "Cameleon" is a marimba solo piece with French and Jazz influence. This piece is composed in the ABA form with a Coda. The A section starts with lyrical, flowing melody that is smooth yet colorful. The B section begins with faster tempo with accent of rhythmic passages to create an energetic and intense second theme, which provides a great contrast with the A section. After a diminuendo and ritardando, it repeats back to A section, and end up with a Coda. "Variations on Japanese Children's Songs" consists of three main sections. The Ostinato and main idea are introduced in the very beginning, and presented with different phrasing and dynamic. The second section consists of several cadenza-like passages. The dynamic contrast and tempo change, the great use of accelerando, retardando and tempo rubato, allows performer to express the passage more freely and colorful. The last section includes many fast shift of dynamic, timbre and register, which combines previous material, build up the climax and a brilliant ending. "Dr. Gradus ad Parnassum" demands mature four- mallet technique to meet the challenges in this short but profound piece. The fast sixteenth-notes-run requires fast and accurate small interval change of single hand and very even double strokes to achieve the flow of each passage. The sixteenth- notes arpeggio figure with accent demands cross sticking to bring out the accent. The mood change in this piece asks for sensitive touching to reach various timbre and to interpret different character of passages. The style of these three pieces is contrast, but these three pieces are technically challenging and virtuosically impressive flourish.

Joint MIMO Radar Waveform and Receiving Filter Optimization

2009-07-06T14:36:00.001-07:00

論文發表人：陳俊仰/加州理工學院/電機系

http://www.icassp09.com/GeneralInformation.asp

多輸入輸出雷達(MIMO Radar)系統使得每個發射天線能傳輸任意波形。這個新的方法比起傳統的傳輸波束形成方法提供了額外的自由度。在最近的文獻中，它已被證明具有很多優點。在本文中，我們考慮使用目標物和雜波的先驗資訊，同時最佳化多輸入輸出雷達的波形和接收濾波器。本文中提出一種新的迭代算法來提升檢測性能。該算法保證信噪比在每個迭代步驟得以改善。計算結果顯示，該方法比現有的設計方法能有更好的信噪比。

The concept of MIMO (multiple-input multipleoutput) radar allows each transmitting antenna element to transmit an arbitrary waveform. This provides extra degrees of freedom compared to the traditional transmit beamforming approach. It has been shown in the recent literature that MIMO radar systems have many advantages. In this paper, we consider the joint optimization of waveforms and receiving filters in the MIMO radar when the prior information of target and clutter are available. A novel iterative algorithm is proposed to optimize the waveforms and receiving filters such that the detection performance can be maximized. The proposed algorithm guarantees that the SINR performance improves in each iteration step. The numerical results show that the proposed methods have better SINR performances than existing design

methods.

How can people's expectation capture business cycle and affect the relationship between housing market volatility and expected housing asset returns?

2009-06-29T10:07:00.001-07:00

論文發表人: 黃美綺 (加州大學河濱分校經濟系博士班)

http://www.gbdi-conference.org/11.html

本論文為美國房屋市場1963至 2007的實證研究。其採用考慮由於心理預期造成的波動反饋效果的模型, 來檢視房屋市場波動和預期房屋資產報酬之正相關性。此外, 將Markov-switching特性融入房屋價格成長率波動, 來觀察此模型是否能反映美國景氣循環。爲與暫時性房價波動區分, 特結合其他相關房市變數, 來估測美國房市長久轉折時點。本研究發現, 依據三個不同轉折點區分之任何時期, 房屋市場波動和其預期資產報酬皆為正相關。此外, 本模型的房價成長高波動時期, 能夠充分反映除了1973-75之外的所有蕭條期。

This paper empirically investigates the housing market during 1963-2007 by incorporating volatility feedback effect to examine if relationship between housing market volatility and expected housing asset returns rate is positive under the framework of Campbell and Hentschel (1991) and extended version by Kim, Morley and Nelson (2004). This model is able to capture the power of economic agents' expectation based on some information availability assumptions by introducing Markov-switching housing market volatility. To determine the breakpoints with permanent structural changes, instead of choosing any convenient break date, I employ Perron and Qu (2006) framework by estimating some bivariate VARs for housing prices and some relevant housing variables. Based on the results from VARs, I choose three break dates--1984Q1, 1990Q1, and 1999Q1. All empirical results indicate that there is significantly negative volatility feedback effect. Importantly, except 1973-75 recession, this model captures all NBER-dated recessions including recession in 2001.

Bilingual Practices: Mexican American Immigrant Children's Code-Switching in Peer Play Interactions in a Bilingual U.S. Preschool

2009-06-29T10:00:00.001-07:00

論文發表人：湯雅婷 (加州大學聖塔芭芭拉分校教育研究所博士班)

http://www.aera.net

會話分析學派的學者嘗試由對話情境中的對話細節去瞭解語碼轉換的現象。本研究採用民族誌研究法，長時間記錄美籍墨裔幼兒在雙語幼稚園中與同儕互動的情況。本研究並採用會話分析法，分析幼兒的互動以及雙語對話。研究結果發現美籍墨裔幼兒善於運用自身的雙語資源，並將語碼轉換做為一種應對技巧，進而影響遊戲中同儕群體互動的參與架構。研究的結果證明雙語教育將對雙語幼兒在社會化的發展上有所助益，並且對美國加州227教育法案提出合理性的質疑。

Recently, researchers working within the framework of conversation analysis have argued that in order to understand code-switching, the analyst must attend to "the details of its local production in the emerging conversational context which it both shapes and responds to" (Auer, 1998). This study analyzes examples of talk from an ethnographic study of children's free play peer interactions recorded at a bilingual preschool program serving Mexican-American families in California. The analysis demonstrates how children use code-switching to shift the local "participation frameworks" (Goodwin, 1990) of their play during moment-to-moment sequences of interaction. Results are discussed in terms of implications for educational policy.

Casimir force between inclusions in a stretchable fluid membrane

2009-06-29T09:58:00.001-07:00

論文發表人: 林香谷 (加州大學河濱分校物理系)

http://meetings.aps.org/Meeting/MAR09/Event/94611

我們計算在可伸展細胞膜表面引入外來物顆粒後因熱微擾產生的熵力。這種熵力可看作是在有限溫度下的喀西米爾力。在我們的模型中考慮了細胞膜因為表面張力與彎曲所產生的能量改變。為了簡化計算，我們考慮兩個圓盤形狀的外來物，藉此，可以讓細胞膜原來的正常模態發生改變，進而造成喀西米爾效應。我們的結果包含了任意強度微擾造成的熵力，其中涵蓋外來物是孔洞，剛性圓盤等等。我們計算也考慮了邊界效應對系統的影響。

We calculate the entropic fluctuational force, a finite- temperature analogue of the Casimir force, between foreign inclusions in a strechable fluid membrane. Specifically, we consider the fluctuations of a planar membrane governed by the full Helfrich Hamiltonian, including the surface tension and both bending rigidity terms. The inclusions are introduced as circular regions where the surface tension and/or bending rigidities are modified from their values on the non-perturbed membrane. Results for arbitrarily-strong perturbations of the membrane, including holes, rigid disks, and edges will be presented.

Structural Health Monitoring for Frame Models with Damaged Joints

2009-06-26T11:52:00.001-07:00

論文發表人:林俊宏 (加州大學聖塔芭芭拉校區機械工程博士班)

http://spie.org/smart-structures-nde.xml

本論文提出一個利用量測結構之動態反應，可用於桁架結構，包括樑、柱、接頭等部位之結構檢測法。此研究包含了一個將複雜的桁架模型簡化的技巧，並以此技巧增強了一個之前提出的結構動態檢測法。我們利用在地震發生時，在每一層樓量測到的結構動態反應，例如加速度、速度、位移等資訊，配合一個將結構中不同區域狀態分離的演算法，使得結構中的損壞可以被偵測以及定位出來。在此論文中，我們利用兩個數值模擬的模型來驗證這個結構檢測法，第一個例子是一個三層樓的桁架結構，另一個例子則是一個類似結構檢測基準模型的四層樓、雙間隔的桁架結構，這兩個例子都成功地驗證了我們提出的結構動態檢測法。

This paper presents a method of detecting and locating structural damages in beams, columns or joints of a frame structure by directly using structural vibration measurements. A previously developed damage diagnosis technique is enhanced by including an equivalently simplified lumped-mass model of the complex frame structure. The parameters derived from the simplified lumped-mass model are used in the damage diagnosis algorithm, while the actual dynamic responses measured from the frame structure under seismic excitation are used as the inputs. The dynamic responses measured from different floors can be decoupled by using the proposed damage diagnosis algorithm. As a result, damages in the frame structure can be detected and located. Numerical examples of a three-story-one-bay steel frame model and a benchmark-liked four-story-two-bay steel frame model are considered to demonstrate and evaluate the usefulness and effectiveness of the present method.

Monolithic 1.58-micron InAs/InP quantum dash passively mode-locked lasers

2009-06-24T09:56:00.001-07:00

論文發表人：林昌億（新墨西哥大學光電所博士班）

http://spie.org/x19316.xml

在這篇論文中，我們報告了在磷化銦基版上生長的砷化銦量子段單積體1.58微米波段被動鎖模雷射元件。此雷射元件的重複頻率可達到18.5千兆赫。Dashes-in-a-well作用區域結構包括了五層受壓應變的AlGaInAs量子井包覆的砷化銦量子段，外圍有30奈米受張力應變的AlGaInAs層。雷射元件共振腔長度為二至三公釐，有著4微米寬的脊形波導管，其波導每隔0.5公釐劃分著電絕緣的正極接觸區塊。我們經由改良的分節觸點測量法得到砷化銦作用區域的模式增益及耗損譜，並確認砷化銦量子段的光電特性是半導體鎖模雷射所需求的。分節的波導管在同樣的DWELL作用區域下被重新焊接成分隔的增益及吸收區塊。我們在在吸收區塊旁的刻面鍍上一高反射膜(95%)，而另一刻面則是自然斷面。為了解共振腔設計及決定增益與吸收段長度的比例關係，我們以微波光子學的角度推導出一個針對兩段式被動鎖模雷射器件的共振腔設計模型。新推導出的理論方程式可經由量測的模式增益與損耗特性數據找出最佳雷射元件腔長設計。

Monolithic InAs quantum dash 1.58-micron passively mode-locked lasers grown on an InP substrate are reported. A repetition rate of up to 18.5 GHz has been realized. The dashes-in-a-well (DWELL) active region consists of 5 stacks of InAs quantum dashes embedded in compressively strained Al_0.20Ga_0.16In_0.64As quantum wells separated by 30-nm undoped tensile-strained Al_0.28Ga0_.22In_0.50As spacers on both sides of the DWELL. 4 micron-wide ridge waveguides with cavity lengths in the range 2-3 mm were fabricated with equal-length, electrically-isolated anode contacts, each 0.5 mm in length. The modal gain and loss spectra of the InAs active region were then measured through the improved segmented contact method, and the characteristics that make InAs quantum dash materials system desirable for semiconductor mode-locked lasers were identified. The segmented waveguides were then reconfigured into mode-locked lasers by wire bonding the segments together to form separate gain and absorber regions that use the same DWELL active region. A highly reflective coating (95%) was applied to the mirror facet next to the absorber while the other facet was cleaved. To assist in the cavity design and determine the relative length of the absorber and gain sections, a model for the cavity geometry of two-section passively mode-locked lasers was studied that is based on a microwave photonics perspective. The new set of theoretical equations was used to find the optimal device layout using the measured modal gain and loss characteristics as input data.

Effects on Hardness and Elastic Modulus for DSS-8 Peptide Treatment on Remineralization of Human Dental Tissues

2009-06-24T09:55:00.001-07:00

論文發表人 : 許家展 (加州大學洛杉磯分校材料科學與工程學系)

http://www.mrs.org/s_mrs/sec.asp?CID=6688&DID=174641

縮氨酸及含有氨基酸的聚合分子特別是含有大量羧酸鹽是被認為可與礦物表面交互反應。這些縮氨酸大部分反應於調解生物礦化成長。在這份研究中，探討DSS-8縮氨酸對再礦化之人類牙齒組織影響。結果表示，經過含有DSS-8縮氨酸之再礦化處理的去礦化的琺瑯質及未處理的象牙質其硬度增加。另外，有添加DSS-8縮氨酸處理的去礦化的琺瑯質及未處理的象牙質其硬度與彈性模數高於未添加DSS-8縮氨酸處理。

Peptides and macromolecules contain amino acid residues, specifically regions rich in carboxylates, as known to interact with mineral surfaces. Those peptides are most active in the mediation of biologically directed mineral growth. In this work, the effects of DSS-8 peptide treatment on remineralization of human dental tissues are investigated. The results show that hardness of demineralization enamel and native dentin increases after remineralization treatment with DSS-8 peptide. Additionally, hardness and modulus of demineralization enamel and native dentine with DSS-8 peptide treatment are higher than that without DSS-8 peptide treatment.

Multi-scale analysis of InSAR time series to estimate variations in topographically correlated propagation delays with application to the Makran Subduction Zone

2009-06-18T12:07:00.001-07:00

論文發表人: 林玉儂(加州理工學院)

Many InSAR observations are plagued by propagation delays that correlate with topographic variations within a given scene. These delays are frequently termed tropostatic delays and are assumed to result from temporal variations in horizontal stratification of the troposphere. We present a robust approach to estimating tropostatic compensation coefficients (K values) that is relatively insensitive to confounding processes (e.g., earthquake deformation, phase ramps from orbit errors, etc). Our approach takes advantage of a multiscale perspective by adopting wavelet decomposition of both topography and observed phase. By decomposing topography and observed phase in a given interferogram into several spatial scales, we determine the bands spanning different characteristic length scales wherein correlation between topography and phase is significant and stable. Our approach also uses the inherent redundancy provided by multiple interferograms constructed with common scenes. We define a unique set of component time intervals, Tint, using a suit of interferometric pairs. The pair-based K values (Kpair) are then combined to estimate temporally consistent values for each time interval (Kint). The Kint values are then recombined to make final values of Kscene in order to correct each interferogram.

We are testing our approach in the region of the Makran subduction zone, located in western Pakistan and eastern Iran, within the influence zone of South Asian monsoon. We use twenty-nine ENVISAT images to develop the time series. Preliminary results find large variations in estimates of Kscene and Kint. Generally, the tropostatic correction accounts for a relatively small portion for the phase observed, although significant effects are found for selected pairs. The typically small impact of the tropostatic correction implies that in the future we must consider more complex dynamic atmospheric models.

差分合成孔徑雷達影像是用來做同震地表變形判釋的重要工具，然而用在震間低幅度的地表變形上，卻有很大的限制，因為低幅與低頻的震間變形行為所產生的訊號容易受到傳輸延遲的干擾，這種延遲與地形起伏呈共變現象，又被稱作對流層延遲，起因於對流層在垂直向分層的時間變化。本研究使用地形與相位間的線性相關模型，建立一個方法以估算其轉移函數K，此方法對於其他地質現象（構造變形、軌道誤差造成的大尺度相位傾斜）相對不敏感，因而能提供較可靠的K值。此多尺度分析法利用小波轉換將地形與差分雷達影像分成數個不同的空間尺度，其中某些特定尺度顯示出較高的地形相位共變關係，而且其所得到的K值比起其他尺度相對穩定，表示不受到其他因素的干擾。本研究同時利用多幅影像所提供的內在冗餘性來建立非重覆性的時間序列，首先我們定義一組非重覆的時間段落Tint，與其對應的轉移函數Kint，則以各差分合成孔徑雷達影像為基礎的轉移函數Kpair便是Kint的線性組合。解此線性系統便可得到Kint的時間序列，並可由其推測所以其他差分合成孔徑雷達影像的Kpair。

我們將此一方法應用在巴基斯坦與伊朗邊界的莫克蘭隱沒帶，該地區曾於1945年發生規模8的強震，並在周圍印度洋海岸造成海嘯災害。我們希望透過傳輸延遲校正可以得到較為精確的震間變形量，進而了解目前在隱沒帶上的應力狀態。測試的結果發現，我們的方法可以在山區得到不錯的校正量，但是校正後影像仍舊呈現出不小的對流層訊號，推測應該與動態的對流層變化諸如局部對流或是背風波有關。這表示我們下一步需要考慮動態對流層變化的校正。

Offset ancient city wall yields plausible slip rate for the Sagaing fault, Burma (Myanmar)

2009-06-18T12:01:00.001-07:00

論文發表人：王昱（加州理工學院地質與行星科學系博士班）

http://www.agu.org/meetings/fm08/

The Sagaing fault offers great potential for paleoseismology study, because it traverses a region with a long history and high rates of sedimentation. Buddhist documents from ancient Pegu (Bago), in southern Myanmar, record 34 strong earthquakes in the past 2.3 millennia. The latest of these is the 1930 Pegu earthquake (M 7.3), which had high intensities along a 90 km stretch from Pegu to the southern coastline of the country.

We have found evidences for surface rupture in 1930 in the stories of village elders and in offset paddy fields. These reports and offsets suggest that coseismic displacement decreased from several meters in Pegu to liquefaction without faulting near Payagyi Township, 15 km farther north. West of Payagyi, the fault trace cuts through and offsets an ancient city wall. The age of the ancient city is uncertain, but descriptions from Burmese history indicate it was built in the late 16^th century, probably about 440 yrs ago.

Determination of the offset of the 440-year-old city wall is possible, but not simple, in part because vertical displacements across the fault have resulted in differential sedimentation on the flanks of the wall. After accounting geomorphologically for the differential sedimentation, the offset of both the outer and inner edges of the city wall appear to have sustained a right-lateral offset of about 6 meters.

This yields an approximate slip rate of 14 mm/yr, which is slightly lower than the slip rate determined by others from GPS geodesy. The number of earthquakes involved in creating the 6-meter offset is currently unknown, but paleoseismic excavations within the ancient city may well yield evidence of discrete offsets that we will be able to ascribe to specific large earthquakes in the historical record. Candidates include historical earthquakes 1582, 1644, 1768, 1830, 1888, 1913 and 1917 C.E.

實皆斷層(Sagaing fault)為南北向貫穿緬甸全境的主要走滑斷層。由於該斷層通過具有長期歷史紀錄及高沉積速率的地區，為一具高潛力的古地震研究區域。

於過去的二千多年中，位於勃古(Bago)的佛教典籍紀錄了南緬甸地區多達34次的強烈地震，最後一次規模7.3的強震發生於1930年，並造成該地區的嚴重死傷。然而，該事件僅留下部分片段的地表破裂紀錄，對於古地震事件的研究並無太多的助益。

本研究透過現地調查及口述歷史的方法，揭露了1930年地震的同震變形可能情境。調查顯示實皆斷層(Sagaing fault)1930年的地表破裂在通過勃古城後即向北遞減，由數公尺遞減至難以辨認的程度。距離勃古城以北15公里處，調查亦發現該斷層穿過一古城遺跡，並錯移該遺跡之北面城牆。雖然至目前為止，對於該遺跡之年代並無科學上的定論，但透過緬甸歷史之描述，我們相信該遺跡應建於16世紀末期，據今約有440年之譜。透過電腦模擬方式，本研究建議該古城牆所紀錄的錯移量約在6-8公尺之譜。

此結果顯示實皆斷層(Sagaing fault)的大約滑移速率約在每年1.4 -1.8 公分之間，與近年的GPS觀測結果相近。目前我們並不清楚這6-8公尺的位移與哪些歷史地震有關，但應不脫公元1582，1644，1768，1830，1888，1913 及1917 的地震事件。對於該遺跡的更進一步調查或可揭露實皆斷層(Sagaing fault)於過去數百年間的詳細活動行為，並將對東南亞該地區的潛在地震災害有更進一步的認識。

Minimally Invasive Parylene Dual-Valved Flow Drainage Shunt for Glaucoma Implant

2009-06-10T11:03:00.001-07:00

論文發表人：林峻暉（加州理工學院電機系博士班）

http://www.mems2009.org/

本篇論文發表了一個由聚對二甲基苯材料所製作，應用於治療青光眼的雙節流閥控制流體之植入式元件。藉由整合的雙節流閥結構，此元件能夠以物理性的方式來排出過多的眼內液體以此來調節眼壓至適當的15-20豪米汞柱。除了基本的功能性微流體元件外，加上為手術而特別增加的設計，例如一個聚對二甲基苯容納管與固定器，也同時整合在此一元件當中，因此可以成功達成最小侵入式，術後無須縫合的手術目標。聚對二甲基苯固定器擁有一個非常深的半圓形溝槽，這是運用乾式薄膜光阻的技術製作而成。由於固定器的存在，可以防止元件在植入眼睛後發生滑動的現象。實驗室的實驗已經成功驗證了此一元件的確可以提供帶通式的流體控制結果，此結果完全可以滿足青光眼醫療上的需求。實驗結果也顯示，後製製程與封裝程序可以將節流閥完整封裝於聚對二甲基苯容納管內而在測試時並無液體滲漏的現象發生。所以此一元件已經適合用於活體實驗的階段。藉由最佳化後的微機電製程與後製製程，此一元件乃是第一個應用於醫療系統當中，可應用於治療青光眼，被動的，零電力消耗，也無須加入任何電路設計的雙節流閥式控制流體植入式元件。

A parylene-enabled microvalved shunt implant for glaucoma drainage is presented in this paper. Enabled by the dual-checkvalve operation, this device can physically drain the extra intraocular fluid and regulate the intraocular pressure (IOP) within the normal range (15-20 mmHg). Improved surgical features, in addition to the functional/microfluidic components, such as parylene-tube carrier and anchors, are also incorporated in such device to realize minimally invasive suture-less implantation, suitable for practical in vivo use. The parylene anchor with very deep semi sphere recess is fabricated utilizing the dry film photolithography technique. With this improved surgical features and the newly developed packaging techniques, the overall finished GDD form factor not only still keeps minimally invasive implantation possible, but also prevents dislodging after subconjuctival implantation. A pressure-bandpass configuration is characterized by on bench verification which illustrates that the results meet medical requirements to treat glaucoma patients. It also shows that the epoxy and photoresist sealing during the packaging and testing procedures secure the system from water leakage extremely well. With the optimized micromachining and post-fabrication process procedures, the developed implant is the first checkvalved glaucoma drainage device (GDD), which is passive, consumes no additional power, and functions without any circuit involved to pursue its medical application.

Lower Frequency Metamaterial-Inspired Magnetic-Based EZ Antennas

2009-06-10T11:02:00.001-07:00

論文發表人：林佳慶 (亞利桑那大學電機與電腦工程研究所博士班)

http://www.nrsmboulder.org/

Many applications have been proposed that use metamaterials (MTMs), artificial materials having engineered electromagnetic properties, to obtain a desired, but unusual electromagnetic behavior. For instance, metamaterial-inspired efficient electrically small antennas have been proposed which have led to an efficacious, electrically-small antenna design methodology and have drawn much attention. Inspired by the properties of MTMs and the ideas associated with this kind of antenna, we have extended the 3D magnetic-based EZ designs which operate at the lower frequency bands. Several 300MHz 3D antenna were fabricated by filling in the dielectric gap with a quartz dielectric spacer. Not only did the quartz spacer provide the desired lower capacitance, it also enhanced the mechanically stability of the fabricated structure. A series of realizations and designs of the 3D antenna and the corresponding measured results was shown that good agreement between the simulation and experimental results was obtained.

現今已有許多應用超常介質材料(matamaterial)來達成一個特別的電磁場行為，例如應用超常介質材料來設計一個有效率且極小天線的概念提供了本篇論文發展的基本設計方式，基於超常介質材料的特性及相關的天線設計方法，我們提出一個工作於300 MHz之3D EZ天線設計方式，為了達到小天線的要求，我們加入石英來提供足夠的電容值以達到天線共振要求，除此之外，石英也幫助了我們在實做天線時增加結構的穏定度，模擬和量測結果證明此天線系統之有效輻射效率大於90%且工作於所設計的頻率。

Sub-monthly Variability in the South American Monsoon System

2009-06-10T11:01:00.001-07:00

論文發表人: 馬席研(加州大學洛杉磯分校大氣及海洋科學系博士班)

http://www.bom.gov.au/events/9icshmo/

本研究利用觀測資料與全球大氣與地表耦合模式的模擬結果，在月內 (sub-monthly) 的時間尺度下，探討亞馬遜雨林中心低層持續的西風與東風期間，南美季風系統的變異度。

觀測與模擬的降雨異常合成圖在巴西西北部和中部與東南部都呈現一個雙極類型。在盛行西風（東風）期間，巴西中部與東南部顯示降雨的正異常(負異常)，這同時也顯示南大西洋輻合區降雨的增強。此外，在盛行西風期間，季風區高層高壓也同時增強，並且位於南美上空的亞熱帶噴射氣流也同樣增強並且更接近赤道地區。

在亞馬遜地區東、西風盛行期間之前，南太平洋850毫巴重力位高度場的時間序列合成圖與該地區主要的低頻變異度(又稱為太平洋南美類型Pacific-South American patterns)非常類似。因此我們認為這個發現顯示了南太平洋溫帶大氣環流的低頻變異度與南美亞馬遜季風風場與降雨變異度的關連性。

We examine the sub-monthly variability of the South American Monsoon System (SAMS) with emphasis on three-day periods or longer during which the anomalous wind at low-levels in central Amazonia is consistently from the west or the east (westerly and easterly wind regimes, WWRs and EWRs, respectively). Our research methodology is based on observational, Reanalysis, and model data. The latter is provided by simulations of an atmospheric general circulation model coupled to an advanced land surface model (AGCM/LSM).

For both wind regimes, the composites of observed and simulated anomalous precipitation show a dipole pattern with poles in northwestern and central-southeastern Brazil. During WWRs (EWRs), precipitation anomalies at the central-southeastern pole are positive (negative), indicating a stronger (weaker) South Atlantic Convergence Zone (SACZ). Furthermore, during WWRs the upper-level monsoon high is stronger and the subtropical jet in the South American sector is stronger and closer to the equator.

Lag composites of geopotential height anomalies at 850mb prior to the establishment of the wind regimes in Amazonia show the development of structures in the South Pacific that resemble the principal modes of variability in that region, which are usually referred to as the Pacific South American (PSA) patterns. This finding suggests that links exist between the wind regimes and the modes of intraseasonal variability over the South Pacific and over South America. Thus, it is proposed that the wind regimes over Amazonia are associated with low-frequency variability in the extratropical circulation.

Persons with Down syndrome Can Dance!

2009-05-12T11:01:00.001-07:00

論文發表人: 陳志佳（亞利桑那州立大學人體肌動學系博士班）

http://www.scapps.org/

Many observations and anecdotes have suggested that persons with Down syndrome (DS) love music and specifically moving to music. The present pilot study videotaped 10 adults with Down syndrome and 10 mental age-matched participants dancing in response to five different types of music (e.g., Classical/Pop, Jazz). Our preliminary results suggest that persons with Down syndrome didn't move rhythmically; however, they were more active and did move more to music than mental age matched participants. While persons with DS had some characteristic movement patterns that were similar with all music types, some persons with DS did adopt specific movement patterns for specific types of music. Furthermore, they clearly enjoyed what they were doing. We suggested music could be a media to improve their motor learning and development. Further research needs to quantify this love of moving to music.

先前研究已經指出唐氏症患者喜好音樂並熱愛隨者音樂舞動。本研究以影像錄影記錄10位唐氏症患者與10位心智年齡相符之受試者在五種不同類型音樂(例如：現代古典音樂、爵士樂)播放下之動作表現模式。我們初步研究結果發現唐氏症患者無法隨者音樂節奏表現出節奏性的律動。然而，他們比心智年齡相符之受試者更能積極隨者音樂擺動與動作展現。大部分唐氏症患者無論在任何音樂類型下均表現出某些相似性且具特徵的動作表現模式。然而某些唐氏症患者卻能針對某些特殊音樂類型表現出特殊之動作模式。因此，我們清楚發現唐氏症患者能夠享受並隨者音樂舞動。因此本研究建議音樂是能夠成為一個適當的媒介提供唐氏症患者作為改善動作學習與發展之工具。針對他們對於音樂的喜愛，我們將進一步研究能量化探討他們的動作行為模式。

BART: A novel laboratory-based instrument to quantify preferred limb use in patients after stroke

2009-05-12T10:59:00.001-07:00

陳淑雅 (南加州大學/生物肌動暨物理治療研究所博士班)

http://www.sfn.org/am2008/

An objective, reliable and valid measure to capture paretic limb use post stroke is critical to investigations seeking to determine a threshold of limb performance that can be used to predict long-term use. The Motor Activity Log (MAL) is a widely used subjective interview of voluntary arm use in daily life. However, there are limitations: (1) it relies on patients' recall; (2) it takes at least 1 hour to administer; (3) most testing items are not appropriate for discordant (paretic ≠ dominant) arm use. A novel laboratory-based measure was developed to quantify limb preference during aiming in a semi-circle workspace, the Bilateral Arm Reaching Test (BART). Twofold Purpose: (1) to develop and parameterize BART; (2) to establish test-retest reliability and concurrent validity of BART in patients post-stroke. The high test-retest reliability suggested that BART is a stable measure. BART has an acceptable validity for capturing voluntary arm use in daily life as indicated by a moderate correlation between AOR and MAL AOU. BART is an objective quantification of voluntary arm use in daily life after stroke. It is easy to administer and may be appropriate for discordant post-stroke patients. Future work: quantification of learned nonuse in patients post-stroke.

一個客觀及兼具信效度可測量日常生活中手功能效用的評估工具，對量化中風治療劑量以決定治療效果門檻的研究來說是非常重要的。近十幾年來，主觀的動態活動日誌(Motor Activity Log; MAL)被廣泛使用來評估日常生活中手功能效用。但是這個評估工具有一些缺點：(1) MAL需要仰賴中風病人的回憶能力；(2) 完成一次MAL所需時間超過1個小時；(3) MAL問卷中大部分的問題不適用在中風後患側手非慣用手的病人身上。在這前提之下，我們發展了一個全新量化中風後日常生活中手功能效用的實驗室評估工具，稱為BART (Bilateral Arm Reaching Test)：兩側上肢伸展測試。本實驗主要目的有二：第一，發展可立即迅速調整參數的評估工具BART；第二，建立中風病人使用BART的測試再測試效度及同時效度。實驗結果發現，中風病人使用BART評估手功能效用時，測試再測試信度很高，顯示BART是一個很穩定的實驗室評估工具。此外，以MAL作為同時效度測量指標，我們建立了可接受的評估中風病人手功能效用的效度。整體來說，BART是一個可客觀量化中風病人日常生活中手功能效用的評估工具，且BART是一個簡單操作並可短時間完成測試的實驗室工具，再者BART可能更適用於中風後患側手非慣用手的病人。未來我們來繼續朝著定量中風病人手功能恢復的目標前進。

Language Change in the Taiwanese Speech Community: The myth of hoo

2009-05-12T10:58:00.001-07:00

論文發表人: 楊惠玲 (亞利桑那州立大學英文系語言學博士班)
http://oregonstate.edu/dept/foreign_lang/lasso/

This paper aims at providing insights into linguistic connections among the speech communities in a multi-cultural society, specifically elucidating linguistic variation and language change among three dialects spoken in Taiwan. Although a strict language policy on Mandarin was formerly implemented in Taiwan, local dialects have been passed down by immigrants from China and their offspring. Some characteristics of these dialects have been maintained in spite of intensive language contact, while others have been merged and transformed.

By utilizing dialectology in conjunction with historical linguistics, researchers have been better able to interpret linguistic variation and language change in Chinese. With a theoretical base drawn from historical linguistics and typology, this study focuses on Mandarin and two Southern Chinese dialects (Southern Min and Hakka) in terms of their causative formulation, mainly from the perspective of syntax, semantics and, to a lesser degree, phonology. This paper relies on research methods such as: literature reviews, corpus analyses, and comparative methodologies, as well as interviews with native speakers of the dialects investigated.

This research differs from others in that it looks into speech variations in the Chinese causatives from a historical perspective, mainly syntactic change and primarily grammaticalization, a linguistic event in which a morpheme changes from a lexical to functional category. The other difference in scope is that of the inclusion of more than one dialect. Most previous research on Chinese causatives has dealt with a single dialect.

A typical causative construction in Chinese is NP₁ + V₁ + NP₂ + V₂, where V₁ is the causative verb or marker. Derived from shi-yi (使役) causative verbs, the Mandarin morphemes rang 讓 and jiao 叫 can serve as V₁ in causative structures (Chang, 2005). The Mandarin morpheme gei 給 is also often used in this structure as well. These three words have been grammaticalized into causative markers in Modern Standard Chinese. The morphemes hoo in Taiwan Southern Min and bun in Hakka serve the same function in expressing causative constructions; however, hoo and bun allow other functions as well. Other constraints also vary from one language to another.

This paper's research questions are: (1) How do these two dialects differ from Mandarin in forming causative constructions? ; (2) Do they share typological characteristics? ; (3) To what extent have the two other dialects been grammaticalized, compared to Mandarin? ; (4) How do all three grammaticalization pathways compare cross-linguistically? And, (5) How does language contact account for the linguistic variation or change in the speech communities in Taiwan?

台灣多元社會中的語言變異：以閩南語中的一個多功能用字hoo為例

本研究旨在探討台灣多語社會的語言變化。研究標的為：國語與台灣閩南語間的差異與共同性。研究理論主要為方言學、歷史語言學與類型學。研究方法為文獻比較法與語料庫分析。具體而言，本研究的焦點放在閩南語中的特殊用語hoo。由於方言尚未有統一的符號表現方式，當本研究論及該字時均以羅馬拼音表之。此字具有多種功能，它既可用於使役句、給予句，也存在於被動結構。本研究希冀找出該字在台灣閩南語中的分歧，以進一步地證明語法化在該語言中的存在與演進。

根據過去的文獻，方言學與歷史語言學的結合為中文語言學者帶來相當重要的語言變異詮釋基礎。本研究以上述理論為出發點，就時間縱向而言盡可能採集相關語言學者之於歷史文獻的探討，包括中西方學界的相關討論與結論。就時間的橫剖面言，作者針對可取得的現存語言資料庫進行語料分析。資料主要來自台灣中央研究院語言所的漢語平衡語料庫、花蓮大漢科技大學的公開閩南語語料庫以及國立台灣清華大學語言所提供之閩南語電視劇語料。

本研究顯示台灣閩南語中的hoo逐漸失去其多元性。換言之，該字已歷經語法化的程序。具體而言，回應連金發(2008)對於khit-hoo逐漸取代單一hoo的在閩南語被動句的用法，hoo的給予用法也顯現分歧性。現存的台灣閩南語語料庫顯示，給予句採用單一的hoo與另一種新結構共存，亦即將一個動詞前綴於hoo而形成另一個複合字。此現象說明了hoo在給予句式中的弱化帶來該字一個重新方析的基礎。以上證實了歷史語言學的語法化現象。此複合字的產生為語言循環中的更新現象，在此基礎上，未來該語言的給予結構將可能產生其他新的字眼。因此，本研究預測前述hoo的原有的多功能性極可能分化為三種明顯不同的語法結構。

CONSTRUCTIONAL MEANING AND MENTAL SIMULATION

2009-05-12T10:56:00.001-07:00

論文發表人: 韓文瑋（夏威夷大學語言所博士班）

http://artsci.case.edu/csdl9/

Constructional theories of grammar propose that grammatical constructions contribute meaning to a sentence beyond that of the individual words. For instance, Goldberg (1995) argues that the ditransitive encodes a transfer-of-possession meaning, while the dative encodes a caused-motion meaning. If grammatical constructions encode meaning in a psychologically real way, then there should be measurable differences in how individual language users interpret dative versus ditransitive sentences. For instance, ditransitive and dative constructions should evoke measurably different mental simulations in understanders. In particular, understanders should more intensely mentally simulate a path when processing a dative sentence than when processing a ditransitive one. Results from a behavioral study showed that participants performed significantly longer physical movements while processing dative sentences, as compared with ditransitive sentences. This suggests that dative sentences more strongly activate path representations in understanders than do ditransitive sentences, confirming the notion that grammatical constructions contribute meaning to the utterances they occur in.

結構語法理論提倡句構語意。人們對語句的理解不單來自對各個詞語的認識；語詞、單字的組合固然賦予語言意義，在句法層次上，不同句子結構亦衍生不同涵義。傳統結構語法分析近趨同義的不同句式，歸納其細微語意表現差異來為結構語法佐證。本研究採用心理行為實驗，探討英語使用者處理兩種可交替代換句式─雙賓式（ditransitive）及與格句式（dative）─時產生的不同行為表現。其結果提供結構語法量化實徵證據。

如果句構語意有其心理真實性，經由實驗分析我們應該可以測量出不同句式的心像理解差異。過往的結構語法分析歸論雙賓式引申所有物的移轉，與格句式強調致使行動路徑。據此理論，我們讓受試者聆聽兩種句型，並執行一無關乎語言理解的「打靶作業」。在每一句子結束之後，受試者移動游標並點選目標物。依變量為反應時間及游標移動距離。實驗結果顯示與格句式之後反應時間較長，由實驗中的對照組可知此反應時間差異並非來自句子字數的不同。此結果支持句構語意理論。儘管兩句式使用一模一樣的內容字，與格句式相較下突顯路徑表徵。

Optimal Stopping Problem with Offers from One of Two Possible Distributions

2009-05-12T10:55:00.001-07:00

論文發表人: 李妍明（南加州大學工業工程系博士班）

http://meetings.informs.org/DC08/

We introduce an optimal stopping problem for selling an asset when the fixed but unknown distribution of successive offers is either f₁ or f₂. The seller has to decide whether to stop or to continue after receiving an offer. A dynamic programming model and some heuristic optimal policies are presented. Using simulation, the performances of the heuristic methods are evaluated and an upper bound for the optimal expected return is derived. We then present a variant of this problem in which the seller now has to set up a reserve price before offers come in. We show that the optimal solution can be obtained by linear programming.

本研究主題為最適停止問題中的資產銷售問題。賣家能夠逐一觀察買家們的出價價格；當賣家拒絕某買家的出價時，必須支付一定成本才能繼續觀察下一個出價；一旦買家的出價被拒絕，賣家不能回頭再選擇將資產銷售給該買家；賣家的主要目標是尋找獲得最大利潤的最佳策略，決定何時該將資產銷售出去。於本研究中，我們假設當出價資訊不充足，僅知來自於兩個可能的機率分配之一時，賣家該如何找出最佳策略。我們應用動態規劃建構並分析數學模型，提出三個啟發式解，並運用模擬來評估啟發式解的利潤與最大利潤的關係。此外，我們亦研究此最適停止問題的變化型，將此假設應用於線上競標機制。此時賣家的決策為在觀察出價前制定銷售底價。我們運用動態規劃與線性規劃，為此問題求得最佳策略。

Constructional Meaning and Mental Simulation

2009-05-05T11:40:00.001-07:00

論文發表人: 韓文瑋（夏威夷大學語言所博士班）

http://artsci.case.edu/csdl9/

Automatic Extraction of Road Intersection Position, Connectivity, and Orientations from Raster Maps

2009-05-05T11:38:00.001-07:00

論文發表人: 蔣耀毅（南加州大學資訊科學系博士班）

http://acmgis08.cs.umn.edu/papers.html

The road network is one of the most important types of information on raster maps. In particular, the set of road intersection templates, which consists of the road intersection positions, the road connectivities, and the road orientations, represents an abstraction of the road network and is more accurate and easier to extract than the extraction of the entire road network. To extract the road intersection templates from raster maps, the thinning operator is commonly used to find the basic structure of the road lines (i.e., to extract the skeletons of the lines). However, the thinning operator produces distorted lines near line intersections, especially at the T-shaped intersections. Therefore, the extracted position of the road intersection and the road orientations are not accurate. In this paper, we utilize our previous work on automatically extracting road intersection positions to identify the road lines that intersect at the intersections and then trace the road orientations and refine the positions of the road intersections. We compare the proposed approach with the usage of the thinning operator and show that our proposed approach extracts more accurate road intersection positions and road orientations than the previous approach.

道路網絡是地圖中一項非常重要的資訊。在整個道路網絡裡面，整組道路交叉的模版(包含道路交叉的位置、道路連接數目及道路方向)不僅足以代表著這個道路網絡的幾何圖型並且自動擷取這些模版會比擷取整個道路網絡更加的容易。在自動擷取道路交叉模版的同時，細化演算法通常會用來產生一個圖素寬的道路，但是細化演算法也同時扭曲了線條的方向而導致自動擷取的道路交叉模版不準確。在這一篇文章裡，我們提供了一個新的方法來追溯地圖上的道路並且擷取準確的道路交叉模組。

Compressed Sensing in MIMO Radar

2009-05-05T11:36:00.001-07:00

論文發表人 : 陳俊仰( 加州理工學院電機工程學系博士班)

http://www.asilomarssc.org/

壓縮感測是一種結合壓縮及採樣的技術，對於在某些變換域有稀疏性質的信號非常有效率。最近，壓縮感測被提出用於雷達系統。當雷達目標在多普勒-距離空間中是稀疏的，壓縮感測回復技術可以有效的重建出目標物。在本文中，我們將這個想法延伸到多進出雷達。在多進出雷達，本文使用壓縮遙感技術去重建目標物於多普勒-距離-角度空間。為了有效地重建目標物，目標物的反射信號的相關性必需要足夠小。本文提出了一種波形設計的方法，以減少目標物反射信號之間的相關性。由於多進出雷達的維度較大，壓縮技術將會是影響力相當大的技術。

Compressed sensing is a technique for efficiently sampling signals which are sparse in some transform domain. Recently, the idea of compressed sensing has been used in the radar system. When the number of targets on the range-Doppler plane is small, the target scene can be reconstructed by employing the compressed sensing techniques. In this paper, we extend this idea to the MIMO radar. In the MIMO radar, the compressed sensing technique can be used to reconstruct the target scene when the signals are sparse in the range-Doppler-angle space. To effectively reconstruct the target scene, it is required that the correlation between the target responses be small. In this paper, a waveform design method is introduced to reduce the correlations between target responses. Because of the increased dimensionality in MIMO radars as compared to SIMO radars, the impact of compressed sensing will be very significant there.

Joint Optimization of Transceivers with Decision Feedback and Bit Loading

2009-04-28T11:42:00.001-07:00

論文發表人: 翁竟智(加州理工學院電機系)

http://www.asilomarssc.org/

收發器的優化問題的MIMO渠道在過去被考慮過使用線性接收器以及與判決反饋（有限元）接收器。聯合優化比特分配，先行編碼器，並均衡在過去被認為只用於線性收發器（收發器與線性先行編碼器和線性均衡器）。也有人指出，利用有限元甚至沒有比特分配的一般結果性能更好，線性收發比特分配。本文提供了一個一般性研究這個的收發器與迫零的制約因素。這是正式表明，當比特分配，先行編碼器，並均衡共同優化，線性收發器和收發器與有限元有相同的性能，即發射功率是相同的某一比特率和錯誤概率。發展本文是基於廣義三角分解(GTD)。這將是表明了廣泛的GTD階級為基礎的系統的最佳解決有限元問題，比特分配。在特殊情況下，線性收發最佳比特分配將成為其中一個解決辦法。

The transceiver optimization problem for MIMO channels has been considered in the past with linear receivers as well as with decision feedback (DFE) receivers. Joint optimization of bit allocation, precoder, and equalizer has in the past been considered only for the linear transceiver (transceiver with linear precoder and linear equalizer). It has also been observed that the use of DFE even without bit allocation in general results in better performance that linear transceivers with bit allocation. This paper provides a general study of this for transceivers with the zero-forcing constraint. It is formally shown that when the bit allocation, precoder, and equalizer are jointly optimized, linear transceivers and transceivers with DFE have identical performance in the sense that transmitted power is identical for a given bit rate and error probability. The developments of this paper are based on the generalized triangular decomposition (GTD) recently introduced by Jiang, Li, and Hager. It will be shown that a broad class of GTD-based systems solve the optimal DFE problem with bit allocation. The special case of a linear transceiver with optimum bit allocation will emerge as one of the many solutions.

Per-Antenna Power Constrained MIMO Transceivers Optimized for BER

2009-04-28T11:41:00.001-07:00

論文發表人: 翁竟智(加州理工學院電機系)

http://www.asilomarssc.org/

本文討論線性收發器的優化問題.在多載波多輸入（ MIMO ）的渠道，每個天線功率的限制。由於在實際執行每個天線是有限的其單獨配備功率放大器，本文採用更支現實的每天線權力的制約，相反傳統的總和權力制約發射機天線。假設完美知識的渠道在發射器和接收器，優化問題可以轉變成一個半正定問題，是可以被解決的凸優化工具。此外，若干客觀職能的MIMO系統，包括平均位誤差率，也可以用此方法解出。

This paper considers the linear transceiver optimization problem for multi-carrier multiple-input multipleoutput (MIMO) channels with per-antenna power constraints. Because in practical implementations each antenna is limited individually by its equipped power amplifier, this paper adopts the more realistic per-antenna power constraints, in contrast to the conventional sum-power constraint on the transmitter antennas. Assuming perfect channel knowledge both at the transmitter and the receiver, the optimization problem can be transformed into a semi-definite program (SDP), which can be solved by convex optimization tools. Furthermore, several objective functions of the MIMO system, including average bit error rate, can also be optimized by the introduction of the majorization theory.

Authentic and Reliable Suspended Solids Measurement Processes for Stormwater

2009-04-28T11:34:00.001-07:00

http://www.envicenter.com/iwa2008/web/index.php?option=com_frontpage&Itemid=1

論文發表人: 詹立成 (加州大學洛杉磯分校土木及環境工程研究所博士班)

總懸浮固體需樣品混合均勻，前期研究低速下易造成實驗誤差，攪拌強度取決於攪拌過程，如人工，機器或其他拌勻方式，及以人工或試管分次樣品，機器自動分次樣品，未定義方式易造成誤差。本研究分析實驗偏差值並且建立最好實驗過程。

實驗依據水及廢水處理標準程序執行，以微矽珠與沉積土為實驗物質，方式有搖勻或拌勻後人工及試管分次樣品，加入緩衝板或方形容器後人工及試管分次樣品，及機器拌勻試管分次樣品。

搖勻或拌勻試管分次樣品較人工分次樣品準確，由於人工分次樣品較難以得到準確容量。拌勻較搖勻準確。以試管分次樣品及250RPM攪拌速度，機器拌勻於直徑小於90毫米顆粒獲得74%回復率，相較直徑大於125毫米顆粒只得8%回復率，歸因較大顆粒沉積於底部。增加攪拌速率會導致渦流現象產生而攪拌不完全，加入緩衝檔板或方形容器可減少渦流現象，但顆粒卻於燒杯角落沉積。人工傾倒較難反應實際濃度，搖勻無法使顆粒分布均勻，導致次樣品濃度不一。加入緩衝檔板或方形容器並不適用於攪拌。在700RPM攪拌速度，小於250毫米懸浮微粒可得到超過95%回復率，大於250毫米可得到72.4%回復率。標準燒杯使用700RPM以上攪拌速度的拌勻方式，與使用試管分次樣品可得到最準確回復率。

The total suspended solids (TSS) standard method requires well-mixed samples for analysis. The previous work has shown that TSS results are unreliable below certain mixing speed. The required mixing intensity depends heavily on the mixing processes. The mixing method can be shaking, stirring, or even not specified. Transferring subsamples can be pouring, pipetting, or automatically distributing by using the churn splitter. The various mixing methods and the lack of a well defined procedure can cause errors in recover. This study analyzes the deviations among mixing processes and establishes the best mixing process for the TSS experiment.

The TSS standard method was performed based on Standard Methods for Examination of Water and Wastewater. Silicon beads and embedded sediments were used in the experiments. Several mixing processes were performed. Pour and pipette subsamples after shaking or after stirring. Pipette subsamples after stirring in the container with baffles or the square shape of the container. Pipette after stirring by the gang-mixer.

Pouring subsamples is less precise than pipetting either after shaking or stirring. It is also more difficult to obtain accurate volumes when pouring. Stirring yields more precise results than shaking. With pipetting subsamples and 250 RPM mixing speed, experiments using gang-mixer show 74% recovery rate of the particles smaller than 90 mm but only 8% recovery rate of the particles larger than 125 mm. Larger particles can be observed at the bottom of the sample collection beaker. Simply increasing mixing speed produces a large vortex when prevents mixing. Beakers with baffles and square container were utilized to eliminate the vortex but resulted in dead zones that trapped suspended solids. The experiments show that pouring has poor recovery rate of the real concentration. Shaking samples may result in partial mixing and uncertain particle concentration of the subsamples. Beakers with baffles and square containers are unsuitable for the mixing. Particles smaller than 250 mm have more than 95% recovery rate and 72.4% recovery rate for those larger than 250 mm at 700 RPM mixing speed. In sum, using stirrers, stirring at the mixing speed of 700 RPM or higher in a regular beaker, and using pipettes transferring subsamples gives the best recovery rate.