It has been recognised that formal methods are useful as a modelling tool in requirements engineering. Specification languages such as Z permit the precise and unambiguous modelling of system properties and behaviour. However some system problems, particularly those drawn from the information systems problem domain, may be difficult to model in crisp or precise terms. It may also be desirable that formal modelling should commence as early as possible, even when our understanding of parts of the problem domain is only approximate. This thesis suggests fuzzy set theory as a possible representation scheme for this imprecision or approximation. A fuzzy logic toolkit that defines the operators, measures and modifiers necessary for the manipulation of fuzzy sets and relations is developed. The toolkit contains a detailed set of laws that demonstrate the properties of the definitions when applied to partial set membership. It also provides a set of laws that establishes an isomorphism between the toolkit notation and that of conventional Z when applied to boolean sets and relations. The thesis also illustrates how the fuzzy logic toolkit can be applied in the problem domains of interest. Several examples are presented and discussed including the representation of imprecise concepts as fuzzy sets and relations, system requirements as a series of linguistically quantified propositions, the modelling of conflict and agreement in terms of fuzzy sets and the partial specification of a fuzzy expert system. The thesis concludes with a consideration of potential areas for future research arising from the work presented here.

隨著商業活動的蓬勃發展、國際間貿易往來頻繁, 銀行所提供的服務及金融商品, 亦順應這些需求不斷增加, 其所扮演的角色及涵蓋的產業已非昔日可比擬; 若是金融產業遭受到衝擊、面臨危機, 很可能會對整個經濟體造成嚴重影響; 因此, 本文將探討何種解釋變數對於銀行營運發生狀況時, 有較佳的解釋能力。文中所選取的解釋變數主要有兩種: 其一來自於常被業界用來分析公司狀況的Altman Z-scores 模型, 本文將採用Altman 對於非 製造業所歸納出的四種財會比率變數, 另一種變數為KMV 模型利用Black and Scholes選擇權評價公式所導的違約距離(distance to default)。於過去的論文, 此兩種模型都常被探討其對公司發生危機時是否具解釋能力, 但於兩者間之比較則少有著墨; 故本文利用2000至2008年台灣的17間上市銀行為樣本, 於Logit 迴歸模型下, 同時以Altman Zscores模型的財會比率變數和KMV 模型的違約距離為解釋變數, 探討何者對於公司的營運狀況發生問題時, 有較佳的解釋能力。實證結果發現, 違約距離對於銀行營運變差的情況, 有較佳且顯著的解釋能力, 故透過檢視違約距離的高低, 將有助於銀行產業及早發現其營運之問題, 以避免情況惡化, 釀成更大的危機。 / As highly development in commercial activities and international trade become more frequently, the role of banks has become much more important than before. If banks are influenced by shocks, the whole economy might encounter serious financial crisis. Therefore, this research aims to discover what variable will have better explanatory power for banks’ operating situation. In the thesis, two kinds of explanatory variables are selected: one is based on the financial accounting ratios from Altman Z-scores model, and the other is distance to default which is derived from Black and Scholes’ option pricing formula. In prior thesis, both types of model have been usually discussed about their individual explanatory power to corporate default risk, but there are few papers comparing them and finding which one is better. Hence, this research takes 17 banks in Taiwan from 2000 to 2008 as samples, and puts them in the same Logit model to find which type of variables has better explanatory power for bank’s operating situation. According to the empirical result, distance to default would perform better than financial accounting ratios, so supervising the distance to default of banks will be useful for banks to find if there are problems in its operation and prevent it from becoming a big trouble in advance.

Title: Is maternal hypotension during pregnancy and/or posterior located placenta associated with increased risk of stillbirth? Design: A retrospective case-controlled study comparing a group of stillbirths with a live born control group matched for maternal age, baby gender, gestational age and year of birth. The purpose of this study was to ascertain whether hypotensive women or women with a posterior located placenta are at increased risk of stillbirth. Two Australian tertiary referral obstetric hospitals were chosen as participating hospitals for this study. All cases with a discharge diagnosis of stillbirth over a five year period at these hospitals were identified and considered as cases for inclusion in the study. An attempt was made to match each case with two controls. After exclusions there were 124 cases and 243 controls. Blood pressure (BP) readings throughout pregnancy were extracted from the medical record of each subject, and summary 'exposure' measures were created. These included: diastolic and systolic readings as well as mean arterial pressure taken at the initial (booking BP), minimum, calculated average, and final reading prior to the birth. Placental position, as determined by midtrimester ultrasound, was also collected. Results: This study found that low Diastolic Blood Pressure (DBP) readings (between 60-70mmHg) throughout pregnancy were associated with a statistically significant increased risk of stillbirth. This trend was seen from the initial reading at booking (OR 1.83 95% CI 1.0-3.2, p=0.03) through to the last taken before the birth (OR 1.53 95% CI 0.9-2.5, p=0.09) including the calculated average over the course of the pregnancy (OR 1.61 95% CI 1.0-2.6, p=0.05) and minimum observed during the pregnancy (OR 2.94 95% CI 0.98-8.8, p=0.05). In addition, this study found a minimum diastolic reading of less than 60mmHg carries a significant risk of stillbirth with a crude odds ratio of 3.5 (95% CI 1.18-10.41, p=0.02). This study did not show a statistically ignificant association of systolic hypotension with stillbirth. However, after combining both systolic and diastolic blood pressures to calculate the mean arterial blood pressure (MAP) the analysis did suggest that women with a minimum MAP between 73-83mmHg were at increased risk of stillbirth (OR 1.69 CI 1.02-2.81, p=0.04). Furthermore, this study found that three MAP readings of less than 83.3 during the course of the pregnancy carries almost twice the risk of stillbirth (adjusted OR 1.99) even after adjusting for race, gravidity, parity, BMI and SGA (and matching for maternal age, gestational age, gender and year of birth.) Women who have a posterior located placenta were statistically more likely to suffer a stillbirth than women who had a placenta in any other position (crude OR 1.64) and this estimate was largely unaffected by adjustment for blood pressure and other putative risk factors (adjusted OR 1.67) Conclusion: In conclusion, this is the first study which specifically examined a stillborn population in order to explore whether maternal hypotension and posterior located placenta impact negatively on stillbirth incidence and the results of this study suggest that both maternal hypotension and posterior located placenta are probably independent contributory risk factors for stillbirth. This means that maternity care providers should closely manage and monitor progress of women who are hypotensive during pregnancy or those whose placenta is posterior; and that effective management strategies need to be developed to care for these women. / Thesis (Ph.D.)--School of Population Health and Clinical Practice, 2007.

<p>Lagen om företagsrekonstruktion infördes den 1 september 1996 och skulle ersätta den gamla ackordslagen. Syftet med den nya lagen var att det skulle bli enklare att rekonstruera krisföretag som bedömdes ha utsikter till en framtida lönsam verksamhet. Genom rekonstruktionsförfarandet får företaget ett rådrum att arbeta med de ekonomiska problemen utan att för tillfället riskera en konkurs. Det har dock visat sig att lagen inte blev den succé många hade hoppats på. Sedan införandet fram till 2006 har endast 1507 företag ansökt om att bli rekonstruerade. Antalet konkurser under samma period uppgick till 88 262, vilket visar på den dåliga genomslagskraft lagen fått. Trots det dåliga genomslag lagen om företagsrekonstruktion har fått, finns lite forskning på området. De få undersökningar som gjorts har mestadels fokuserat på att kartlägga vilka typer av företag som väljer att ansöka om rekonstruktion. Exempelvis vilken organisationsstruktur de har, storlek på företaget, hur länge de har varit verksamma och dess geografiska läge. Genom åren har ett flertal statistiska modeller utvecklats för att kunna predicera en konkurs innan den inträffar. Den mest kända och allmänt vedertagna modellen är Z-score, utvecklad av Edward I Altman. Vi blev nyfikna på om denna forskning även går att applicera på företag som väljer att ansöka om företagsrekonstruktion? Med kunskap om de finansiella förutsättningarna, kan kanske fler företag med möjlighet att genomgå en företagsrekonstruktion identifieras och eventuellt räddas från en annars oundviklig konkurs. Denna uppsats syftar till att utifrån en finansiell analys studera skillnader i den ekonomiska ställningen hos rekonstruktionsföretag respektive konkursföretag. Då vi utifrån en stor mängd data vill generalisera resultatet på en hel population har vi använt oss av en kvantitativ undersökningsmetod. Vidare har vi använt oss av ett deduktivt angreppssätt och skapat en teoretisk bas innan den empiriska studien tagit vid. Den teoretiska referensramen behandlar främst teorier kring lagen om företagsrekonstruktion, nyckeltal och konkurspredicering. De modeller och nyckeltal vi valt ut, har utifrån tidigare undersökningar visat sig bra vid bedömningen av ett företags nuvarande och framtida finansiella ställning. I undersökningen framkom att de företag som ansöker om företagsrekonstruktion har lika dåliga och i vissa avseenden sämre finansiella förutsättningar än de företag som gick direkt i konkurs. Även Z-scoremodellen indikerade att rekonstruktionsföretagens finansiella ställning var sämre än konkursföretagens.</p>

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"This work was supported by the Center for Energy Policy Research of the M.I.T. Energy Laboratory."

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