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Background: Procedure cancellations in outpatient interventional radiology (IR) can lead to delays in diagnosis, lost revenue and underutilization of department resources. Current practice at some centers is the use of registered nurses (RN) to conduct outpatient pre-procedure telephone screening. However, same-day procedure deviations requiring cancellations remains high. This quality improvement (QI) project evaluated the effectiveness of an advanced practice registered nurse (APRN) driven pre-procedure clinic to assess same-day cancellations, days to procedure, and cost-effectiveness compared to RN telephone screening for biopsies. Objectives: To determine if an APRN interventional radiology pre-procedure clinic will reduce cancellation rates, days to procedure, and lost revenue in comparison to nurse telephone screening for outpatient biopsies. Methods: Using a comparative design, 111 patients (47 APRN pre-procedure clinic group and 64 historical RN telephone group) were examined via retrospective medical record reviews between August 1, 2019 to January 1, 2020 [RN group] and August 1, 2020 to January 1, 2021 [APRN group]. Patient information extracted were demographics, insurance type, anesthesia classification, biopsy type, cancellation and reason, and days to procedure referral. Estimated lost revenue was calculated based on procedures cancelled and summed per group based on procedure reimbursement, facility and clinic fees, and professional fees [physician, RN or APRN]. Descriptive and inferential statistics were used to assess group differences. Results: There were no statistically significant differences between patient groups for demographics and clinical conditions (similar types of biopsy procedures). The most common reasons for cancellation in both groups were patient factors, including elevated blood pressure and acute illnesses. There were significantly more cancellations in the RN group (18/28%) in comparison to the APRN group (9/14%; p=0.018). Additionally, the RN group had greater numbers of days to procedure (36.2 � 21 vs. 21.3 � 18, mean � SD, p

This dissertation investigates the existence of surjective and split surjective maps between modules. A classic result in this direction is Serre's Splitting Theorem, which gives a lower bound on the maximum rank of a free summand of a finitely generated projective module. Here, the underlying ring is assumed to be commutative and Noetherian with a finite-dimensional maximal spectrum. De Stefani, Polstra, and Yao generalize this theorem by removing the projective condition. Bass extends Serre's Splitting Theorem by considering a module-finite algebra over the ring and replacing the Noetherian condition on the ring with a Noetherian condition on the maximal spectrum. We generalize all of these results by replacing the free summand with a direct sum of copies of a finitely presented module. This requires us to replace rank with a more abstract notion that we call splitting capacity. We generalize Serre, De Stefani-Polstra-Yao, and Bass in a second way by studying the number of summands isomorphic to one module that can appear in a quotient of another module. This is related to the notion of surjective capacity. In the case of finitely generated modules over a Dedekind domain, we show that we can even characterize when a surjective or splitting capacity is equal to a fixed nonnegative integer. In a separate case, we can guarantee when there exists a split surjective map of a special form. This allows us to extend cancellation theorems by Bass and De Stefani-Polstra-Yao, which provide criteria for when two modules with isomorphic direct-sum complements in a larger module are isomorphic. The complement in each of these theorems is assumed to be finitely generated and projective, although each theorem easily reduces to the case in which the complement is a rank-one free module. We show that we can replace the rank-one free module with a finitely presented homothetic module. As a consequence, our work reveals a cancellation property shared by ideals of finite-dimensional Noetherian normal domains and canonical modules of finite-dimensional Cohen-Macaulay rings.

BACKGROUND: There is a need to identify the populations at high risk of nonadherence to outpatient lung cancer appointments in order to reduce the delay from diagnosis to treatment. The patient navigation system, which helps patients with barriers navigate the health care system, was examined to see if the correct high-risk groups were being addressed. METHODS: A case-control study with 195 subjects from the lung cancer clinics at Boston Medical Center (BMC) was conducted examining three nonadherence case groups: no-shows (n=40), cancelations (n=64) and combined (n=20). Nonadherence was defined as any patient who was a no-show for at least one appointment or who canceled more than one appointment over the three month study period. The combined group incorporated both of these factors. The patients were stratified by 10 patient characteristics, including patient navigation. Odds ratios (ORs) and 95% confidence intervals (CIs) were used for the analysis. A second analysis was done on patients in the patient navigation program (n=33) to determine if the high risk groups identified were being addressed. This was done using ORs and 95% CIs. RESULTS: This study has shown that there are certain patient groups in the lung cancer clinics at BMC that are at higher risk of being nonadherent to lung cancer outpatient appointments. Among those are Hispanic/Latino patients, Spanish and Haitian Creole speaking patients, small cell lung cancer (SCLC) patients, and those patients who have Medicaid, and with late stage lung cancer patients at significantly higher risk (no-shows: OR-5.26 (1.85, 14.95), cancelations: OR-2.49 (1.12, 5.54), combined: OR-12.49 (1.48, 105.46)). Patients in the patient navigation system were also found to be at significantly higher risk of nonadherence (no-shows: OR-3.85 (1.72, 8.65), cancelations: OR-4.13 (1.89, 9.00), combined: OR-5.15 (1.93, 13.72)) than those not in the program. Some patients were also found to be at significantly decreased odds of nonadherence, including those who were: 1000-1999 days post diagnosis (no-shows: OR-0.14 (0.03, 0.59), cancelations: OR-0.20 (0.06, 0.65), combined: OR-0.07 (0.01, 0.64)); 2000-2999 days post diagnosis (no-shows: OR-0.09 (0.01, 0.80), cancelations: OR-0.06 (0.01, 0.50)); aged 71-75 (cancelations: OR-0.25 (0.08, 0.79)). The subset analysis with the patient navigation data yielded no statistically significant results. CONCLUSIONS: The study identified high-risk populations within the total lung cancer population at BMC that should be addressed by the patient navigation program. This study demonstrated that while the program does have its flaws, it is decreasing the odds of nonadherence of many of the high-risk populations.

Because of vehicle ride motion, an operator on board a moving vehicle will tend to impose unintended forces on a manual control interface. This phenomenon is called Biodynamic feedthrough. Biodynamic feedthrough occurs in two scenarios, which may he distinguished by whether the machine under control is an auxiliary machine or the vehicle itself. In auxiliary machine control, Biodynamic feedthrough simply degrades manual control performance. In vehicle control, Biodynamic feedthrough forces close a loop around the manual control interface and vehicle, possibly leading to oscillations that may jeopardize safe vehicle operation. This dissertation presents a model of the human-machine system comprising the biomechanics and volitional manual control activity of the human operator and the dynamics of the vehicle and manual control interface. In the construction of the biomechanics model a distinction is made between the transmittance from vehicle acceleration to Biodynamic force and the driving point impedance at the control interface. The biomechanics model leads to a system identification experiment that identifies the transmittance using measurements of vehicle acceleration and interaction force between the operator's hand and a temporarily immobilized control interface. The estimated transmittance becomes the foundation for a model-based feedthrough cancellation controller. System identification results revealed similar but sufficiently distinct estimates for the various subjects, which prompted the construction of individualized cancellation controllers for each subject. The efficacy of the individualized cancellation controllers was tested in two experiments, each with twelve subjects. The first experiment involved the auxiliary machine control scenario and the second the vehicle control scenario. In auxiliary machine control experiments, the controller improved human performance in a pursuit tracking task as indicated by a 27% reduction in root mean square average tracking error and 32% increase in time on target (p < 0.05). The vehicle control tests characterized tracking performance and disturbance rejection simultaneously. The cancellation controller successfully suppressed oscillations and reduced root-mean-square average tracking error by 45% and improved time on target by 14% (p < 0.05).

Third generation wireless systems are being brought into operation rapidly. Multiuser detection is a key technology that can substantially increase the system capacity. Subtractive interference cancellation is a major category of multiuser detection. Due to their lower complexity, subtractive interference cancellation approaches are attractive for the practical implementation of multiuser detection. This thesis begins with a brief study of several multiuser detection techniques followed by an investigation of subtractive interference cancellation techniques. Two basic schemes, successive interference cancellation (SIC) and parallel interference cancellation (PIC) are discussed in detail and other schemes based on these two, a hybrid and a groupwise scheme, are also introduced. Both SIC and PIC have disadvantages. Consequently, a multistage groupwise weighted interference cancellation (MGWIC) scheme that is flexible in practical implementation and has good performance is proposed and analyzed. The analysis and simulation for a simplified case are presented. The implementation and performance under other conditions are also discussed.

Let W = W($\alpha\sb{1},\dots,\alpha\sb{\rm n})$ be an element of a free group $\Phi$ with basis $\{\alpha\sb{1},\alpha\sb{2},\alpha\sb{3},\dots\}$ and let G be a group with presentation G = $\ \cong$ F/N, for F the free group with basis X, and N the normal closure of R in F. A solution of an equation W$(\alpha\sb{1},\dots,\alpha\sb{\rm n})$ = 1 in a group G is a homomorphism $\zeta$ such that W($\zeta\alpha\sb{1},\dots,\zeta\alpha\sb{n}$) = 1 in G. This solution is called free if $\zeta$ = $\pi$h for h a map from $\Phi$ into F such that hW = 1 and $\pi$ is the canonical map from F onto G. Schupp first studied solutions of quadratic equation W = 1 in small cancellation groups, and showed that W = 1 with nonpositive Euler characteristic $\chi$(W) has only free solutions in G provided the presentation G = $$ satisfies a small cancellation condition C(p) and T(q), where p and q depend on the characteristic of the quadratic word W. His argument had two steps: (1) pass from W = 1 to a set of cancellation-free equations U = 1; (2) show that no U = 1 has a non-free solution $\zeta$U in G, by means of a van Kampen diagram M on the surface defined by $\zeta$U. We eliminate Schupp's first step by considering modified van Kampen diagrams M*, where the label on the boundary $\partial$M* is not required to be reduced. We can then identify occurences of $\zeta\alpha\sb{1},\dots,\zeta\alpha\sb{\rm n}$ on $\partial$M* to obtain a closed surface S with M* now as a tessellation of S, and thus complete Schupp's argument. We also find it advantageous to replace van Kampen diagrams by the dual pictures introduced by Rourke, and modified diagrams by corresponding modified pictures. We use this method not only to recover Schupp's results for small cancellation groups, but also to obtain analogous results for small cancellation quotients of free products (a case treated also by Anderson), of amalgamated products, and of HNN-extensions.

A solution to the problem of rejecting sinusoidal disturbance inputs with unknown amplitudes, frequencies, and phases is presented. The solution is based on using the Youla parametrization of stabilizing controllers to construct a set of stabilizing controllers for the given plant, and searching, online, within this set for a controller that achieves regulation. Three discrete time controller adaptation algorithms are presented and their convergence properties analyzed. The robustness properties of the proposed approach, in the continuous time case, to uncertainties in the plant coprime factor representation is also investigated. Using averaging techniques, it is shown that with slow adaptation, with the initial conditions of the adaptive system close to their desired values, and with appropriately bounded perturbation terms, the adaptive system maintains its performance. Motivated by problems in noise cancellation, the problem of disturbance rejection, described above, using an FIR controller and a gradient type adaptation algorithm is analyzed. Conditions for the adaptive system to achieve regulation are also presented. The adaptive regulation algorithms presented above for discrete time systems were experimentally evaluated on a noise cancellation experiment. The algorithms yielded good results for some disturbance frequency ranges with reduction in the disturbance response of up to 50 dB. At other disturbance frequency ranges, the adaptive control system did not perform well. The possible link between the deterioration of the adaptive system performance and the nonlinearities in the plant is suggested.

อัตราการเลื่อนหรือการงดส่องกล้องตรวจหลอดลม ใน พ.ศ. 2550 สูงถึงร้อยละ 6.32 ทีมหัตถการปอดจึงนำปัญหานี้เข้ามาวิเคราะห์หาสาเหตุ จนได้แนวปฏิบัติในการเตรียมผู้ป่วยก่อน ส่องกล้องตรวจหลอดลม ประกอบด้วย ข้อมูลการเตรียมตัวการทำหัตถการและภาวะแทรกซ้อน ต่างๆ ให้แก่ผู้ป่วยและนำมาสู่การปฏิบัติในปี พ.ศ. 2551 ถึงปี พ.ศ. 2555 ผู้ศึกษาได้ศึกษาข้อมูล ย้อนหลังเพื่อเปรียบเทียบอัตราการเลื่อนและงดส่องกล้องตรวจหลอดลมระหว่างก่อนและหลังใช้ แนวปฏิบัติจากปี พ.ศ. 2551 ถึง พ.ศ. 2555 พบว่า ในปี พ.ศ. 2551 มีจำนวนผู้ป่วยที่มารับบริการ ส่องกล้องตรวจหลอดลมมี 502 ราย มีการเลื่อนและงดส่องกล้องตรวจหลอดลม 21 ราย คิดเป็น ร้อยละ 4.18 ถึงแม้ว่าจำนวนผู้มารับบริการส่องกล้องจะมากขึ้นเรื่อยๆ แต่หลังจากเริ่มใช้แนวปฏิบัติ ในการเตรียมผู้ป่วยส่องกล้องตรวจหลอดลม อัตราการเลื่อนและงดส่องกล้องลดลงทุกๆ ปี ลดเหลือร้อยละ 1.12 ในปี พ.ศ. 2555 และยังคงมีการใช้และมีการพัฒนาแนวปฏิบัติเพื่อลดอัตรา การเลื่อนและงดส่องกล้องตรวจหลอดลมอย่างต่อเนื่อง