Finding the minimal convex polygon on a set of points in space is of great interest in computer graphics and data science. Furthermore, doing this efficiently is financially preferable. This thesis explores how a novel variant of bucketing, called the Iterative orthant scan, can be applied to this problem. An algorithm implementing the Iterative orthant scan was created and implemented in C++ and its real-time and asymptotic performance was compared to the industry standard algorithms along with the traditional textbook convex hull algorithm. The worst-case time complexity was shown to be a logarithmic term worse than the best teoretical algorithm. The real-time performance was 47.3% better than the traditional algorithm and 66.7% worse than the industry standard for a uniform square distribution. The real-time performance was 61.1% better than the traditional algorithm and 73.4% worse than the industry standard for a uniform triangular distribution. For a circular distribution, the algorithm performed 89.6% worse than the traditional algorithm and 98.7% worse than the industry standard algorithm. The asymptotic performance improved for some of the distributions studied. Parallelization of the algorithm led to an average performance improvement of 35.9% across the tested distributions. Although the created algorithm exhibited worse than the industry standard algorithm, the algorithm performed better than the traditional algorithm in most cases and shows promise for parallelization. / Att hitta den minsta konvexa polygonen för en mängds punkter är av intresse i ett flertal områden inom datateknik. Att hitta denna polygon effektivt är av ekonomiskt intresse. Denna rapport utforskar hur metoden Iterative orthant scan kan appliceras på problemet att hitta detta konvexa hölje. En algoritm implementerades i C++ som utnyttjar denna metod och dess prestanda jämfördes i realtid såsom asymptotiskt mot den traditionella och den mest använda algoritmen. Den nya algoritmens asymptotiska värsta fall visades vara ett logaritmiskt gradtal sämre än den bästa teoretiska algoritmen. Realtidsprestandan av den nya algoritmen var 47,3% bättre än den traditionella algoritmen och 66,7% sämre än den mest använda algoritmen för fyrkantsdistribution av punkterna. Realtidsprestandan av den nya algoritmen var 61,1% bättre än den traditionella algoritmen och 73,4% sämre än den mest använda algoritmen för triangulär distribution av punkterna. För cirkulär distribution var vår algoritm 89,6% sämre än den traditionella algoritmen och 98,7% sämre än den vanligaste algoritmen. Parallellisering av vår algoritm ledde i medel till en förbättring på 35,9%. För vissa typer av fördelningar blev denna prestanda bättre. Även då algoritmen hade sämre prestanda än den vanligaste algoritmen, så är det ett lovande steg att prestandan var bättre än den traditionella algoritmen.

Difficulties exist with designing and testing on a model scale. The purpose of this study is to examine variations in the flow field of a submarine due to hull/propulsor interaction and Reynolds scaling. The scope of this study includes the simulation of the flow past a 1) five-bladed marine propeller with 0° skew, 2) unappended submarine hull, 3) forward propelled submarine with asymmetrical stern appendages, and 4) submarine in crashback with asymmetrical stern appendages. The bare hull simulations are conducted for three different length scales: small model scale, large model scale, and full scale. The isolated propeller and appended submarine simulations are conducted on the large model scale. It is of interest how sensitive the various flow characteristics are to Reynolds number and the turbulence model. All simulations are at 0° angle of attack, and validated with experimental data where available.

No description available.

<p>Given colourful sets S_1,..., S_{d+1} of points in R^d and a point p in R^d, the colourful linear programming problem is to express p as a convex combination of points x_1,...,x_{d+1} with x_i in S_i for each i. This problem was presented by Bárány and Onn in 1997, it is still not known if a polynomial-time algorithm for the problem exists. The monochrome version of this problem, expressing p as a convex combination of points in a set S, is a traditional linear programming feasibility problem. The colourful Carathéodory Theorem, due to Bárány in 1982, provides a sufficient condition for the existence of a colourful set of points containing p in its convex hull. Bárány's result was generalized by Holmsen et al. in 2008 and by Arocha et al. in 2009 before being recently further generalized by Meunier and Deza. We study algorithms for colourful linear programming under the conditions of Bárány and their generalizations. In particular, we implement the Meunier-Deza algorithm and enhance previously used random case generators. Computational benchmarking and a performance analysis including a comparison between the two algorithms of Bárány and Onn and the one of Meunier and Deza, and random picking are presented.</p> / Master of Science (MSc)

No / Ambulance service demand is increasing in the United Kingdom. A common speculative view makes a link between this rise in demand, deprivation, and certain medical conditions. This study explored factors infl uencing English ambulance service demand in two areas of differing socioeconomic status. Adopting a causal comparative design, the study compared the numbers of life-threatening calls that Yorkshire Ambulance Service receives and serves in two geographical areas within the Hull and East Riding area. The area of lower socioeconomic status generated signifi cantly more life-threatening calls than the area of higher socioeconomic status; these calls often supported younger patients (mean age 59 years versus 71 years) for breathing diffi culties (29% versus 14.5%) more commonly. Tackling inequality will require a whole-systems approach, effective leadership, and recognition of the benefi ts of understanding difference. A key relationship will entail engaging with seldom heard communities.

Arbetet är till grund för högskoleingenjörsexamen i maskinteknik som har utförts tillsammans med företaget Swede Marine Propulsion som tillverkar och installerar styrsystem på fartyg. Syftet med arbetet var att genom inlärda kunskaper under utbildningen optimera ett fartygs bränsleförbrukning sett till hur mycket marin tillväxt som fartyget har på skrovet. Detta för att minska bränsleförbrukningen och därmed minska utsläppen för fartyget.  För att undersöka detta har en omfattande litteratursökning genomförts med hjälp av relevant teori och beräkningar. Simulering och visualisering har genomförts i MATLAB. Samt har de framtagna modellerna implementerats i iX Developer och företagets styrsystem. Resultatet som påvisades är att det totala motståndet för fartyget ökar exponentiellt sätt till ökad hastighet genom vattnet. Resultatet visar även att de framtagna modellerna går att implementera i ett övervakningssystem vilket ger möjlighet att följa tillväxten på fartygsskrovet under drift.  Slutsatsen är att implementera denna typ av övervakningssystem skulle bidra till bättre medvetenhet då det är dags att rengöra skrovet. Detta skulle potentiellt minska både bränsleförbrukningen samt bränslekostnaderna för fartygen. Även att det finns möjlighet till vidareutveckling av systemet genom att ta hänsyn till flera faktorer såsom luftmotstånd, vindar och vattenströmmar. Men också i form av att justera styrningen av fartyget sett till hur mycket tillväxt som förekommer på skrovet exempel som att öka motorvarvtalet vid ökad tillväxt. / The report is the basis of a bachelor's degree in Mechanical Engineering. The work was done with Swede Marine Propulsion, a company specializing in manufacturing and installing steering systems on ships. The purpose of the project was to optimize a ship's fuel consumption. This was done by using the knowledge acquired during the education and it will focus on the amount of marine growth on the hull. The overall project was aimed at reducing fuel consumption and thus lowering emissions from the ship. To solve the objectives of the project, an extensive literature review was conducted, utilizing relevant theory and calculations. Simulations were carried out in the form of MATLAB graphs. The implementation of calculations was put into the program iX Developer and the company's steering system. The results showed that the total resistance of the ship exponentially increases with higher speeds through the water. By implementing a monitoring system that can assess how fuel consumption varies with different levels of hull growth, the result can be observed. The conclusion drawn is that implementing this type of monitoring system would provide better insight into when hull cleaning is necessary. This would reduce both fuel consumption and fuel costs for the ship. There is potential for further development of the system by considering factors such as air resistance, winds, and water currents. Lastly, an additional action could be increasing the engine RPM in response to increased growth.

論文名稱：可轉換公司債存續期間之分析 校所組別：國立政治大學金融研究所 畢業時間：九十年度第二學期 提要別：碩士學位論文提要 研究生：陳嘉霖 指導教授：陳松男博士 論文提要及內容： 本研究在分析可轉債的存續期間，在存續期間的衡量上是採用有效存續期間法；而在可轉換公司債的評價上，假設股票價格服從幾何布朗寧運動，無風險利率的變動符合Hu1I-white利率模型，並且考量利率與股票報酬之間的相關性，建立可轉換公司債評價六元樹形圖。 本研究分別針對到期期限長短、價內外程度、股價波動度、利率波動度、股價與利率相關係數及票面利率等六項參數，作可轉換公司債存續期間的敏感度分析，研究結果為：1 加入贖回條款後，可轉債的存續期間高於未加任何條款下的可轉債存續期間。2 加入賣回條款後，可轉債的存續期間低於未加任何條款下的可轉債存續期間。3 加入贖回及賣回候款後，可轉債的存續期間會介於僅含贖回條款與僅含賣回條款的存續期間之中。4 距到期日愈長可轉債的存續期間愈高。5 愈價外的可轉債其存續期間愈高。6 股票波動度愈高，可轉債的存續期間愈低。7 利率波動度增加則可轉債的存續期間上升。8 股票價格與利率相關係數由正至負，可轉債的存續期間上升。9 若贖回權愈小，則票息上升會增加可轉債的存續期間。 關鍵字：可轉換公司債、存續期間、有效存續期間、六元樹、Hull-white、利率模型 / Title of Thesis: Anatomy of the Convertible Bond Duration Name of Institute: Graduate Institute of Money and Banking, NCCU Graduate Date: June, 2002 Name of Student: Chen, Chia-Lin Advisor: Dr. Chen, Son-Nan Abstract: This thesis uses effective duration method to anatomize the convertible bond duration. With the assumptions that stock price follows Geometric Brownian Motion and risk-free interest rate follows Hull and White model, we built a hexanomial tree to value the convertible bond. This thesis analyses the effects of the six parameters . They are maturity date, the ratio of the stock price versus the strike price, the correlation between stock return and interest rate, stock return volatility, interest rate volatility, and coupons. The conclusions include nine points. First, the value of convertible bond duration including call clauses is higher then pure convertible bond duration. Second, the value of convertible bond duration including put clauses is lower than pure convertible bond duration. Third, the value of convertible bond duration including both call and put clauses is between only including call or put clauses ones. Fourth, the longer the time to maturity is, the higher the convertible bond duration is. Fifth, the higher the ratio of the strike price versus the stock price is , the higher the convertible bond duration is. Sixth, the higher the stock volatility is , the lower the convertible bond duration is. Seventh, the higher the interest rate volatility is , the higher the convertible bond duration is. Eighth, the value of the correlation between stock return and interest rate increases from a negative value to a positive one, then the convertible bond duration increases. Ninth, if the value of call right is very small , the convertible bond duration will increase by the increasing of the coupon . Keywords: Convertible Bond, Duration, Effective Duration, Hexanomial Tree, Hull and White Interest Rate Model

This is a historical documentary research study across Neva Leona Boyd (1876-1963). The theoretical perspective is based on the historical perspective of knowledge from ancient Greece to the approach of modern symbolic interactionism. The study shows that Boyd, who was Viola Spolins teacher, was a proponent of the modern view of group play theory. 1909 she founded Chicago School for Playground Workers, later transformed to the Recreation Training School. Until 1927, the school entered in Hull-House initiated by Jane Addams. The school was incorporated with Northwestern University. Boyd also worked at other schools and the Illinois Department of Public Welfare, where she designed a recreational program for the mentally ill. Contemporary with Boyd was George H. Mead and John Dewey. Boyd's previous work turns out to have some connection to Sweden when Boyd collected and systematized games from different geographical regions of the world. Boyd’s group play theory are identified and described. Boyd’s group play theory highlights the importance of leadership and the intimacy leaders manage to create in group work.

市場上為了因應投資人的需求，推出來越來越多樣化的結構式產品。結構型商品雖然標榜保本、高配息、高預期報酬，但仍然依照產品結構與連動標的不同，而有相當的投資風險。所以投資人應做好基本功課與認知，才能在投資連動債時明哲保身。 基於上述的理由，本文希望可以透過對結構式債券的評價、分析，讓投資人更了解投資結構式債券所面臨的風險與報酬，避免投資人因為不了解結構式債券的特性而遭受損失，或是因為不了解結構式債券而降低了投資的意願。 個案一為雙重結構利率債券，採用的評價方式為：先利用無套利Hull and White利率模型建構與市場式一致的利率期間結構，再搭配路徑函數的方式展出每日的利率樹，經過轉換後就可根據條款倒推求算利率連動債券的價格。 個案二為通貨膨脹連動信用債券：先採用Duffie and Singleton的方式建構信用曲線，求出違約邊際機率後；再透過Monte Carlo的方式模擬消費者物價指數來計算每期配息。在已知每個節點的預期現金流量後，就可利用倒推的方式求解信用連動債券的價格。

信用衍生性商品可規避或轉移信用風險，為金融機構有效管理信用風險的利器。而信用連結票券可視為結合普通票券與信用違約交換的結構型商品，使得票券的發行者得以規避其交易對手的信用風險，投資者也可藉由承擔信用風險而享受投資報酬率增加的益處。 本文採用無套利的利率模型Hull-White三元樹來建構利率期間結構，可得到與市場利率期間結構一致的利率期間結構。在假設資產違約回收率為外生變數下，採用實務界常用的方法(Duffie and Singleton,1999)建構信用曲線，以求出邊際違約機率。在已知每個節點上的預期現金流量下，利用回推法可計算出信用連結票券的價值。