Dynamic modeling of web purchase behavior and e-mailing impact by Petri net

In this article, the authors introduce Petri nets to model the dynamics of web site visits and purchase behaviors in the case of wish list systems. They describe web site activities and their transition with probability distributions and model the sequential impact of influential factors through links that better explain web purchase behavior dynamics. The basic model, which analyzes site connections and purchases to explain visit and purchase behavior, performs better than a classical negative binomial regression model. To demonstrate its flexibility, the authors extend the wish list Petri net model to measure the impact of e-mailing intervals on visit frequency and purchase.internet; wish list; e-mail; Petri net; dynamic model

Crosscap numbers and the Jones polynomial

We give sharp two-sided linear bounds of the crosscap number (non-orientable genus) of alternating links in terms of their Jones polynomial. Our estimates are often exact and we use them to calculate the crosscap numbers for several infinite families of alternating links and for several alternating knots with up to twelve crossings. We also discuss generalizations of our results for classes of non-alternating links.Comment: 27 pages. Minor corrections and modifications. To appear in Advances of Mathematic

Stability and triviality of the transverse invariant from Khovanov homology

We explore properties of braids such as their fractional Dehn twist coefficients, right-veeringness, and quasipositivity, in relation to the transverse invariant from Khovanov homology defined by Plamenevskaya for their closures, which are naturally transverse links in the standard contact $3$-sphere. For any $3$-braid $\beta$, we show that the transverse invariant of its closure does not vanish whenever the fractional Dehn twist coefficient of $\beta$ is strictly greater than one. We show that Plamenevskaya's transverse invariant is stable under adding full twists on $n$ or fewer strands to any $n$-braid, and use this to detect families of braids that are not quasipositive. Motivated by the question of understanding the relationship between the smooth isotopy class of a knot and its transverse isotopy class, we also exhibit an infinite family of pretzel knots for which the transverse invariant vanishes for every transverse representative, and conclude that these knots are not quasipositive.Comment: 23 pages, 8 figures. Updated to most recent versio

Colored Jones polynomials without tails

We exhibit an infinite family of knots with the property that the first coefficient of the n-colored Jones polynomial grows linearly with n. This shows that the concept of stability and tail seen in the colored Jones polynomials of alternating knots does not generalize naively.Comment: 5 pages, 1 ca

hcnABC Operon Transcription of Pseudomonas putida Under Varying Iron and Oxygen Concentrations and Culture Age

The species Pseudomonas putida produces hydrogen cyanide (HCN) through the transcription of the hcnABC operon. Previous research by Myrna Biswas (2010) demonstrated that microaerobic +FeCl3 cultures had the greatest HCN production, but the effects of varying iron and oxygen levels on HCN production were unclear. Isaac Kim (2011) assessed HCN production of P. putida in sand versus soil using different iron concentrations and found that iron was necessary for HCN production. The purpose of this experiment was to determine how the hcnABC operon is affected by varying levels of iron and oxygen, and the age of bacteria culture. To test this, P. putida was grown under four conditions: the presence of iron, the absence of iron, with aeration, and without aeration. At 8, 18, and 30 hours, the cultures were assessed for HCN production and cell density. HCN production was measured via bioluminescence; light emission occurs whenever HCN is produced because the modified form of P. putida contains the luciferase gene. The cell density was determined using spread plating. Bacterial cultures with iron and minimal aeration had higher bioluminescence levels, suggesting these conditions promote HCN production, but these results were not significant (F(3,2) = 0.561, p = 0.05)

Developing Predictive Models for Risk of Postoperative Complications and Hemodynamic Instability in Patients Undergoing Surgery

Patients undergoing high-risk surgeries are often at higher risk of developing hemodynamic instability during surgery resulting in poor postoperative outcomes. This is usually associated with significantly increased postoperative morbidity and mortality, which therefore makes the early identification of these critical events and those patients at risk of postoperative complications crucial. With these motivations in mind, we first created a large deidentified research dataset of surgical case medical records from University of California, Irvine Medical Center (UCIMC) matched with physiological waveforms as well as intermittent vital sign values, lab values, and ventilator settings. To our knowledge, such a dataset does not currently exist for the intraoperative environment. We hope that creating a such a dataset will allow for advances in machine learning for intraoperative care. Using medical data from UCLA, we have developed deep neural network models to classify the risks of postoperative mortality, acute kidney injury, and reintubation utilizing readily available intraoperative information. Our risk scores were compared to currently commonly used risk indices ASA and Surgical Apgar as well as logistic regression. While the deep neural network models performed better than the risk scores and logistic regression, clinicians require additional information to assess what led to increased risk of complications. To address this, we also assessed the use of generalized additive neural networks (GANNs) to create a graphical look at how different features contributed to the risk of in hospital mortality. Finally, we were also interested in predicting critical intraoperative events to allow for time for the clinician to avoid such events. We focused on intraoperative hypotension as it is easier to define and has been shown to lead to increased risk of acute kidney injury, stroke, and myocardial injury. For the hypotension prediction models, we looked at the arterial pressure waveform and EMR data as inputs. Overall, these aims address a gap in current clinical decision guidance and support to reduce adverse events during surgery as well complications after

겨울도시를 위한 기후민감형 도시설계 — 캐나다 에드먼턴 오픈스페이스 사례를 중심으로 —

학위논문 (석사) -- 서울대학교 대학원 : 공과대학 협동과정 도시설계학전공, 2020. 8. Yumi Lee.본 연구는 캐나다 에드먼턴의 미래 오픈스페이스에 대한 계획과 가상의 설계를 제안하여 겨울을 포함한 모든 계절에 활용할 수 있도록 하는 것을 목적으로 한다. 본 연구의 결과는 기후민감형 도시설계에 대한 고려사항이 겨울도시에서 연중 내내 기능적인 공간을 만드는데 필수적인 부분이라고 주장한다. 현재까지 설계된 대다수의 오픈스페이스는 일년내내, 사계절 동안 기능할 수 없다. 겨울은 항상 실내에 머물기 위한 계절이었고, 여름은 항상 야외활동을 즐기는 계절이었다. 이러한 사고방식은 전 세계의 계획 관행에 뿌리내렸고 겨울 민감형 계획으로의 변화를 조금씩 시작하고 있다. 1980년 이후 컨퍼런스 및 세계 행사들은 겨울 생활 문제를 인정해왔지만, 현재까지 계획관행은 여전히 여름의 사고방식에 바탕을 둔 디자인이다. 겨울과 계절에 따른 온도변화가 우리의 일상에 영향을 미치며, 특히 겨울철에 디자인방식은 공간이 어떻게 사용되는지에 많은 영향을 줄 수 있음을 이해하는 것이 중요하다 낮은 기온, 미끄러움, 어두움과 같은 불편함은 겨울철 야외 공간을 계획하는 데 고려되지 않는 요인들이다. 본 연구의 목적은 캐나다 북부 도시 에드먼턴에서 기후민감형 설계요소들을 활용하여 미래의 공공 도시 공간을 가상으로 설계하는 것이다. 본 연구는 캐나다 에드먼턴에 있는 미래 웨어하우스 캠퍼스 공원(Warehouse Campus Park)의 가상설계를 위해 기존문헌, 설문조사 및 심층인터뷰의 결과를 적용했다. 설문조사 결과는 공공 공간을 사용하는 주된 이유가 축제나 이벤트와 같은 프로그램을 위한 것임을 보여준다. 미래 공간의 설계는 축제일이 아닌 날에도 사용자를 끌어들일 수 있도록 연중 기능성의 요소를 통합하는 것이 필수적이다. 기후민감형 설계의 주요 장벽은 운영 및 유지 관리 문제뿐만 아니라 겨울은 견뎌야하며, 환영받지 못하는 계절이라는 사고방식을 포함한다. 에드먼턴 있는 도시계획가와의 인터뷰에서 에드먼턴 겨울 디자인 가이드라인(Winter Design Guidelines)의 가장 큰 장애물은 해당 문서가 비규제적이어서 시행하기 어렵다는 것이다. 그러나 최근 몇 년 동안 연중 사용 가능한 공간에 대한 민간 개발자 및 커뮤니티의 관심이 증가하고 있다. 심층 인터뷰의 대상자에게 제시된 개념적 설계는 에드먼턴 시가 지역사회 녹색공간 조성을 검토하고 있음을 단적으로 보여준다. 에드먼턴 다운타운이 가장 부족한 것은 열린녹지공간과 어린이 놀이 공간인 만큼 미래의 디자인에서 이러한 요구를 충족시키는 것이 중요하다. 에드먼턴의 도시 형태와 계획 관행을 바꾸는 것은 느리게 진행되어 왔으며, 겨울도시를 위한 기후민감형 도시설계는 거의 10년 전에 도입되었지만, 이러한 설계는 여전히 도시의 개발자들에게 상당히 새로운 개념이다. 겨울도시를 위한 기후민감형 도시설계는 공공 오픈스페이스 공간뿐만 아니라 일반적인 공공 영역에도 적용 되어야한다. 도시설계와 계획의 사전 단계에서 구체적인 고려를 하지 않는 한 추운 날씨와 겨울의 불편함은 계속해서 겨울을 즐기는데 장애가 될 것이다. 본 연구의 설계는 완벽한 디자인을 제시하는 것이 아니라, 북부 국가에서 매우 필요한 기후민감형 도시설계의 주제에 관여하는 설계이다. 본 연구의 결과는 도시 디자이너들이 추운 겨울 동안 어떻게 다양한 문화와 사람들의 요구를 충족시킬 수 있는지를 알려주는 데 도움이 될 것이다.This project proposes recommendations and a hypothetical design of a future public space in Edmonton, Canada that will be functional in all seasons, including the winter. The results of this research argue that climate sensitive design considerations in the early stages of planning and design are a vital part of creating year-round functional space in winter cities. Winter was always the season to stay indoors, and the summer was to enjoy the outdoors. This mindset caused the designs of the public realms to lack for four season, year-round usage. Conferences and world events since the 1980s acknowledged the difficulties of winter living but planning practices to date are still design based on the summer mindset. Although there has been neglect for addressing winter discomforts in Nordic cities, winter sensitive considerations are slowly beginning to be a topic of discussion. It is essential to understand that winter and the change of seasonal temperatures affect our annual daily lives, and design considerations can severely impact how spaces are used, especially in the winter. Discomforts such as coldness, slipperiness, and darkness are some of the neglected considerations for planning outdoor spaces in the winter season. The purpose of this study was to hypothetically design a future public urban space using climate-sensitive considerations in the northern city of Edmonton, Canada. This study applied recommendations and feedback from existing literature, questionnaire results, and in-depth interviews into the design proposal of the future Warehouse Campus Park in Edmonton, Canada. Results from the questionnaire illustrated that the main reasons for using public spaces were for programming, such as festivals and events. Future spaces must incorporate elements of year-round functionality that could attract users even on non-festival days. The main barriers that climates sensitive design considerations included operational and maintenance issues, and the mindset that winter continues to be a season that needs to be endured and not celebrated. Interviews with local planners determined that the most significant hurdle to the incorporating climate sensitive design considerations in Edmonton, was that tie Winter Deign Guidelines are non-regulatory, making it difficult to enforce. However, in recent years, there has been an increase in interest from private developers and communities for year-round usable spaces. The conceptual designs presented in the in-depth interview outlined that the City of Edmonton is looking at creating a community green space. Downtown Edmonton lacks in open green spaces and childrens play areas; therefore, it is crucial to account for those needs in future designs. It is essential to understand that changing the urban form and planning practices in Edmonton has been a slow process. Although the introduction of winter city design was nearly ten years ago, designing for climate sensitive considerations is still a relatively new concept for developers in the city. Climate sensitive design considerations not only apply to public open spaces but to the public realm in general. This project informs how urban designers can cater to diverse cultures and needs of the population during the colder winter months. Cold temperatures and winter discomforts will continue to be a barrier to the winter enjoyment unless preliminary stages of planning and design include detailed climate sensitive considerations. The purpose of the design proposal was to address winter discomforts in Edmonton and engage in further discussion in the topic of climate sensitive considerations for northern cities.1.0 Introduction 1 1.1. Background 1 1.2. Winter Cities Movement 3 1.3. Research Questions 4 1.4. Research Purpose 4 1.5. Project Scope 5 1.6. Methodology 6 2.0 About Edmonton 7 2.1. General Information 7 2.2. Edmonton Weather 9 2.3. Winter City Edmonton 9 2.4. Downtown Edmonton 12 2.5. Edmontons Green Network Strategy 15 2.6. Warehouse Campus Neighbourhood Central Park 15 2.6.1. Downtown Public Places Plan 17 3.0 Literature Review 18 3.1. Introduction 18 3.2. Outdoor Comfort 18 3.2.1. Thermal Comfort 18 3.2.2. Wind Comfort 21 3.3. Winter City Design 24 3.3.1. Barriers to Winter City Design 24 3.3.2. Recommendations for Winter City Design 26 3.4. Designing for the User Experience 32 3.4.1. Space for All Users 32 3.4.2. Challenges of Downtown Open Spaces 33 3.4.3. Year-round Public Places 34 3.4.4. Human Scale Elements 35 3.4.5. Crime Prevention Through Environmental Design (CPTED) 36 4.0 Site Planning 38 4.1. Introduction 38 4.2. Questionnaire 38 4.2.1. Purpose 38 4.2.2. Methodology 39 4.2.3. Design 39 4.2.4. Limitations 40 4.3. Questionnaire Results 41 4.3.1. Reasons and barriers of using public spaces in the winter 45 4.3.2. Perceptions of designing for climate sensitive spaces 48 4.3.3. Vision for the Future Warehouse Campus Park 52 4.3.4. Conclusions 59 4.4. Warehouse Campus 60 4.4.1. Introduction 60 4.4.2. Site Visit 61 4.5. Site Analysis 64 4.5.1. Surrounding Conditions 65 4.5.2. Environmental Conditions 74 5.0 Design Proposal 83 5.1. Guiding Principles 83 5.2. Proposed Programming 84 5.2.1. Conceptual Designs 85 5.3. In-Depth Interview 87 5.3.1. Winter Design Guidelines 88 5.3.2. Potential for Winter Activities 91 5.3.3. Climate Sensitive Considerations 95 5.3.4. Conceptual Design Evaluations 100 5.4. Proposed Design 107 5.5. Detailed Programming 110 6.0 Conclusion 120 6.1. Designing for Winter Cities 120 6.2. Project Limitations 121 6.3. Future Considerations 122 Bibliography 124 Appendix 129 Abstract in Korean 136Maste