Design of an Adaptive Controller for Cylindrical Plunge Grinding Process

In modern competitive manufacturing industry, machining processes are expected to deliver products with high accuracy and good surface integrity. Cylindrical plunge grinding process, which is a final operation in precision machining, suffers from occurrence of chatter vibrations which limits the ability of the grinding process to achieve the desired surface finish. Further, such vibrations lead to rapid tool wear, noise and frequent machine tool breakages, which increase the production costs. There is therefore a need to increase the control of the machining processes to achieve shorter production cycle times, reduced operator intervention and increased flexibility. In this paper, an Adaptive Neural Fuzzy Inference System (ANFIS) based controller for optimization of the cylindrical grinding process is developed. The proposed controller was tested through experiments and it was seen to be effective in reducing the machining vibration amplitudes from a 10-1 µm to a 10-2 µm range

Dynamic Modeling of Chatter Vibration in Cylindrical Plunge Grinding Process

Cylindrical plunge grinding process is a machining process normally employed as a final stage in precision machining of shafts and sleeves. The occurrence of chatter vibrations in cylindrical plunge grinding limits the ability of the grinding process to achieve the desired accuracy and surface finish. Moreover, chatter vibration leads to high costs of production due to tool breakages. In this paper, a theoretical model for the prediction of chatter vibration in cylindrical grinding is developed. The model is based on the geometric and dynamic interaction of the work piece and the grinding wheel. The model is validated with a series of experiments. Results show that variation in the grinding wheel and work piece speeds, and in-feed lead to changes in the vibration modes and amplitudes of vibration

Assisted partner notification services to augment HIV testing and linkage to care in Kenya: study protocol for a cluster randomized trial

Background: HIV case-finding and linkage to care are critical for control of HIV transmission. In Kenya, >50% of seropositive individuals are unaware of their status. Assisted partner notification is a public health strategy that provides HIV testing to individuals with sexual exposure to HIV and are at risk of infection and disease. This parallel, cluster-randomized controlled trial will evaluate the effectiveness, cost-effectiveness, and feasibility of implementing HIV assisted partner notification services at HIV testing sites (clusters) in Kenya. Methods/design Eighteen sites were selected among health facilities in Kenya with well-established, high-volume HIV testing programs, to reflect diverse communities and health-care settings. Restricted randomization was used to balance site characteristics between study arms (n = 9 per arm). Sixty individuals testing HIV positive (‘index partners’) will be enrolled per site (inclusion criteria: ≥18 years, positive HIV test at a study site, willing to disclose sexual partners, and never enrolled for HIV care; exclusion criteria: pregnancy or high risk of intimate partner violence). Index partners provide names and contact information for all sexual partners in the past 3 years. At intervention sites, study staff immediately contact sexual partners to notify them of exposure, offer HIV testing, and link to care if HIV seropositive. At control sites, passive partner referral is performed according to national guidelines, and assisted partner notification is delayed by 6 weeks. Primary outcomes, assessed 6 weeks after index partner enrollment and analyzed at the cluster level, are the number of partners accepting HIV testing and number of HIV infections diagnosed and linked to care per index partner. Secondary outcomes are the incremental cost-effectiveness of partner notification and the costs of identifying >1 partner per index case. Participants are closely monitored for adverse outcomes, particularly intimate partner violence. The study is unblinded due to practical limitations. Discussion This rigorously designed trial will inform policy decisions regarding implementation of HIV partner notification services in Kenya, with possible application to other parts of sub-Saharan Africa. Examination of effectiveness and cost-effectiveness in diverse settings will enable targeted application and define best practices. Trial registration ClinicalTrials.gov NCT01616420

Scale-up of assisted partner services in Kenya: assessing linkage to care, integration and costs

Thesis (Ph.D.)--University of Washington, 2021Despite marked progress in achieving universal 95-95-95 targets, gaps still exist, especially in improving individual awareness of HIV status. According to the 2018 Kenya Population-based HIV Impact Assessment (KenPHIA) report, approximately 79.5% of individuals were aware of their status, 96.0% were on antiretroviral therapy, and 90.6% were virally suppressed. Men were less likely to be aware of their HIV status compared to women (72.6% vs 82.7%) necessitating HTS strategies to effectively target this ‘hard-to-reach’ group. HIV assisted partner services (aPS), or healthcare provider supported notification of sex partners to newly diagnosed HIV-positive individuals, have been used to bridge this gap in HIV testing, and have been shown to be safe, effective, and cost-effective. aPS was scaled up within the national HIV testing services (HTS) program in Kenya in 2016 after World Health Organization (WHO) recommended the intervention. Our objective was to assess linkage to care, integration, and costs of scaling up aPS within the national HTS program in Kenya. In the first study, we used data from nine facilities randomized to receive immediate aPS in a cluster-randomized trial conducted in Kenya. We estimated linkage to care - defined as HIV clinic registration - and ART initiation separately for index clients and their sex partners. We found that only two-thirds of newly diagnosed HIV-positive sex partners, and known HIV-positive sex partners not enrolled in care at study enrolment, linked to care after receiving aPS. However, once linked to care, ART initiation was high (>85%) regardless of whether the participant was an index client, newly-diagnosed or known HIV-positive sex partner not previously linked to care. We recommend that HIV aPS programs optimize HIV care for these individuals, especially those who are younger and single. In the second study, we used an integrated conceptual framework to assess the extent of aPS integration, institutionalization, and sustainability in routine HTS programs. This study was conducted within the aPS scale-up project – an implementation science study to implement and evaluate the effectiveness of aPS when integrated within routine HTS, and assess implementation outcomes including implementation fidelity, acceptability, demand, and costs. We conducted semi-structured key informant in-depth interviews with aPS stakeholders at national, county, facility and community levels, and found that aPS was well integrated into the national HTS program within two years of scale-up. Funding limitations, human resource constraints, and low community awareness were noted as major barriers to service provision and long-term sustainability. To overcome these barriers, we recommend increased resource allocation for aPS (funding, human resources) and community health volunteer-facilitated community-level awareness. In the third study, using a payer perspective, we estimated the cost of integrating aPS into routine HTS within the aPS scale-up project in Kisumu and Homa Bay counties. We conducted microcosting, analyzing costs by start-up (August 2018), and recurrent costs one-year after aPS implementation (Kisumu: August 2019, Homa Bay: January 2020), and conducted time-and-motion observations. The average weighted incremental cost of integrating aPS into the existing HTS program was $7,485.97 per facility per year, with recurrent costs accounting for approximately 90$34.54, $42.50,$108.71 and $152.28, respectively, and varied by county and facility type, with larger volume facilities, especially county and sub-county hospitals, having higher total incremental costs and lower average unit costs. The largest cost drivers were personnel (49%) and transport (13%). We found significant cost variations across facilities offering aPS with high volume facilities having low average unit costs per MSP. We recommend facility prioritization to improve efficiency in resource allocation, especially healthcare personnel, potentially reducing the time and cost spent on delivering aPS. This dissertation contributes to the growing implementation science literature on aPS and highlights the need to prioritize resources as funding support towards HIV programs declines. As aPS is scaled-up, especially in resource-limited settings, policymakers and implementers will need to regularly review program data to identify sub-groups of PLWH requiring additional support before linking to HIV care and treatment services, and address communication gaps on aPS. Future research on cost-efficient strategies optimizing healthcare worker allocation during aPS is also critically important

Case finding among sexual partners to HIV positive individuals in Cameroon.

Thesis (Master's)--University of Washington, 2017-08Background: Heterosexual transmission of HIV accounts for a significant proportion of new HIV infections in sub-Saharan Africa with individuals unaware of HIV status at risk of transmitting the virus to their sexual partners. Partner services (PS) have been in use at the Cameroon Baptist Convention Heath Services (CBCHS) program to promote partner notification, early HIV testing, diagnosis and initiation to treatment for sexual partners to newly diagnosed HIV positive individuals (index persons). The goal of this study is to define the scalability, effectiveness and safety of partner services within the CBCHS PS program. Methods: We conducted a secondary analysis of CBCHS program data from 2007 to 2015 to evaluate the overall scale and partner notification outcomes; using data from 2014-2015, we determined index person (IP) and program factors associated with HIV case-finding; as well as adverse outcomes including partnership dissolution, loss of financial support and physical intimate partner violence (IPV). Descriptive analyses were used to define the overall scale of the program; and adverse outcomes at enrolment and follow-up, overall and stratified by gender. Logistic regression with clustering on the IP was used to describe factors associated with HIV case finding. Results: Overall, the CBCHS program interviewed 18,730 IPs who mentioned 21,057 sexual partners (index: partner ratio = 1:1.08) with a 10-fold increase in number of individuals that occurred mainly from 2007- 2010 before slowing down from 2011 - 2015. Between 2014 and 2015, 1261 IPs and 1357 sexual partners were mentioned. IPs were mainly female (63.8%), median age: 36 years (Interquartile Range [IQR]: 30, 43), married monogamous: 47.9% and seen at rural facilities (70.1%). Sexual partners were male (61.3%), median age 36 years (IQR: 30, 42), and married (57.0%). Ninety percent (n=1224) of the 1357 sexual partners, were notified in-person either by the IP or the health advisor and were offered HIV testing services. HIV prevalence among the 1224 notified sexual partners was 27.2% [previously diagnosed: 170/1224, 13.9%; newly diagnosed HIV positive: 163/1224, 13.3%]. HIV case finding was less likely to be associated with health advisor notification compared to IP notification [adjusted odds ratio [aOR] = 0.66, 95% confidence interval [CI]: 0.47, 0.93]. 19.7% of the IPs reported a history of IPV at enrolment to the PS program (female: 24.2%, male: 15.8%). On IP follow-up after receipt of PS, 61 (6.3%) had partnership dissolution, 15 (1.5%) had lost financial support while 11 (1.1%) sustained physical IPV. Three clients of the eleven reporting physical IPV after receiving PS (27.3%) attributed it to the intervention. Discussion: The CBCHS PS program was scalable, safe and had high HIV case finding compared with other HIV testing methods. IPV was relatively common in Cameroon. However, very few IPs receiving PS reported adverse outcomes following receipt of partner services. Partner services can be a useful component of routine HIV services to augment HIV testing to individuals at risk of HIV acquisition in sub-Saharan Africa countries

Assessment of client satisfaction with service delivery models at the Kenyatta National Hospital voluntary counseling and testing center

Submitted in partial fulfillment of the requirements for the Degree of Masters of Business AdministrationIntroduction: High quality service is critical to client satisfaction by affecting retention and loyalty. The main service delivery models within the healthcare industry are vertical and the integrated. Kenyatta National Hospital (KNH) Voluntary Counseling and Testing (VCT) has used the vertical model since inception. However, with over 50% of HIV infected clients in Kenya unaware of their HIV status, the integrated model was adopted to improve VCT service delivery. We assessed the relationship between client satisfaction and service delivery models at KNH VCT, and evaluated staff views. Methodology: Cross-sectional analysis was carried out on 196 clients (stratified random sampling) and 24 VCT staff (convenience sampling). Participants were consented and structured questionnaires administered. Data analysis was conducted using SPSS (Statistical Package for Social Sciences) Version 16. Descriptive statistics were used to report the socio-demographic characteristics. Multivariate analysis using Pearson’s Chi-square test and Multivariate Analysis of Variance (MANOVA) was used to establish and test the strength of relationship between satisfaction and type of service delivery model. Results: Clients had a high level of satisfaction with KNH VCT services. People were rated highest (4.74) while physical infrastructure was rated lowest (4.13). There was no significant differences in satisfaction between vertical and integrated models except in overall booking process (p=0), waiting time before booking (p=0), waiting time before counseling (p=0), and adequacy of pre-test counseling session (p=0.003). The staff scored people highest (4.40) and physical infrastructure (3.97) with no significant differences between the two models. Waiting times was rated lowest overall. There was a significant difference in strength of relationship with clients consistently rating services higher than staff in all parameters. Conclusion: Clients rated KNH VCT services highly with staff receiving the highest ratings and physical infrastructure the lowest; similar to staff perspectives. Improvements in physical infrastructure and waiting times will likely improve overall satisfaction

STATUS OF THE TEACHING AND LEARNING OF JAPANESE LANGUAGE IN TERTIARY INSTITUTIONS IN KENYA

Japanese language is one of the major languages and the eighth most powerful language in the world. In Kenya, the Japanese language is taught in some universities and middle-level tertiary institutions. However, a large number of learners study the language at the basic level, and only a few of them progress to the advanced levels of the language. There is a need to establish the cause of the high rate of attrition with a view to propose remedial measures necessary for the enhancement of progression rates. In this paper, the status of the teaching and learning of the Japanese language in tertiary institutions in Kenya is investigated. The study focused mainly on instructional methods and instructional resources employed in the teaching of the language. Data was collected through questionnaires, interviews and classroom observations. The study revealed that teachers blend Grammar Translation, Direct and Communicative Language Teaching methods during instructions. It was further seen that Kanji script is not taught in some of the institutions and that though learners are exposed to authentic listening resources, they are not exposed to authentic reading resources. In addition, the instructional resources employed in the learning of the language do not contain local cultural content and therefore, the learners are not adequately exposed to aspects of local context during instructions. Lack of emphasis on Kanji in the language curricula was identified as the main factor contributing to high dropout rates and hampering the progression of learners of the Japanese language to advanced levels.  Article visualizations

Client satisfaction with service delivery models at the Kenyatta National Hospital Voluntary Counselling and Testing Center (VCT)

Objective: To compare client satisfaction with processes, staff, and physical infrastructure between vertical and integrated service delivery models.Design: Cross-sectional study.Setting: Kenyatta National Hospital (KNH).Participants: Adult participants receiving HIV testing service (HTS) at KNH’s inand out-patient departments.Main outcome measures: Client satisfaction was rated using a 5-point Likert scale. Multivariate analysis was used to compare client satisfaction with processes, staff, and infrastructure in the two models. Results: Enrolled clients enrolled were mainly female (61%), aged 32 years in married monogamous relationships (48%). Clients reported a high level of satisfaction with KNH HIV testing services, with married clients more likely to be satisfied compared to single clients (relative risk, RR: 1.05, 95% CI: 1.00 – 1.10, pvalue: 0.037). Clients were more likely to be satisfied with the processes and physical infrastructure in the vertical model, though waiting times were significantly longer compared to the integrated model.Conclusion: Clients were more satisfied with the vertical HTS model. Service improvements in processes and physical infrastructure in the integrated model will likely improve overall client satisfaction

Assisted partner notification services are cost-effective for decreasing HIV burden in western Kenya

Background: Assisted partner services (aPS) or provider notification for sexual partners of persons diagnosed HIV positive can increase HIV testing and linkage in Sub-Saharan Africa and is a high yield strategy to identify HIV-positive persons. However, its cost-effectiveness is not well evaluated. Methods: Using effectiveness and cost data from an aPS trial in Kenya, we parameterized an individual-based, dynamic HIV transmission model. We estimated costs for both a program scenario and a task-shifting scenario using community health workers to conduct the intervention. We simulated 200 cohorts of 500 000 individuals and projected the health and economic effects of scaling up aPS in a region of western Kenya (formerly Nyanza Province). Findings: Over a 10-year time horizon with universal antiretroviral therapy (ART) initiation, implementing aPS in western Kenya was projected to reach 12.5% of the population and reduce incident HIV infections by 3.7%. In sexual partners receiving aPS, HIV-related deaths were reduced by 13.7%. The incremental cost-effectiveness ratio of aPS was $1094 (US dollars) (90$823–1619) and $833 (90$628–1224) per disability-adjusted life year averted under the program and task-shifting scenario, respectively. The incremental cost-effectiveness ratios for both scenarios fall below Kenya's gross domestic product per capita ($1358) and are therefore considered very cost-effective. Results were robust to varying healthcare costs, linkage to care rates, partner concurrency rates, and ART eligibility thresholds (≤350 cells/μl, ≤500 cells/μl, and universal ART). Interpretation: APS is cost-effective for reducing HIV-related morbidity and mortality in western Kenya and similar settings. Task shifting can increase program affordability