Community-based health insurance in ethiopia : enrollment, memebrship renewal, and effects on health service utilization

Atnafu, Ayalneh Asmamaw Seoul National University 2018 국내박사

Community-Based Health Insurance in Ethiopia: Enrollment, Membership Renewal, and Effects on Health Service Utilization Ayalneh Asmamaw Atnafu Dept. of Health Care Management and Policy The Graduate School of Public Health Seoul National University Background: Community-Based Health Insurance (CBHI) received a considerable attention as a mechanism of health care financing and a potential alternative for a user fee in many low and middle-income countries. The Ethiopian government has introduced different measures to implement pre-payment schemes including CBHI as of 2010. In this dissertation, three sub-studies were designed and implemented to explore 1) The determinants of CBHI enrollment, 2) the magnitude and factors associated with CBHI membership renewal, and 3) the association between CBHI enrollment and health service utilization in Northwest Ethiopia. Methods: The main research design of the study was a case-comparison community based cross-sectional household survey linked to the health facility survey supplemented with a concurrent qualitative component. The study populations were all eligible households for CBHI in 15 selected clusters in five districts. A multi-stage cluster sampling was employed to obtain a representative sample for the three sub-studies. Applying a structured questionnaire, 2,008 households and 7 health centers were surveyed. Additionally, 8 focus group discussions (four with CBHI members and four with non-members) and 5 in-depth interviews were conducted to supplement the quantitative findings. A classical multivariate logistic regression, mixed-effect logistic regression, and bivariate-probit regression along with a thematic analysis of the qualitative data were used for the data analysis. Results: The findings from the enrollment study showed that household-related factors such as age, education, self-rated health status, perceived quality of health services, household size, knowledge and information (awareness) about CBHI were the main influential factors affecting enrollment into CBHI in the study area. Additionally, participation in informal associations, such as local credit associations, and health facility factors in terms of availability of laboratory tests significantly influence probability of enrollment. The findings from the membership renewal study showed that 36% of the participants were not willing to renew their membership for the next period. The results confirmed that once the households are enrolled in CBHI, factors related to institutional trusts, such as trust in public health facilities and trust in CBHI schemes, and inconvenience of the premium collection were the main influential factors to renew membership. Moreover, poor self-rated health status and perceived quality of healthcare services are correlated with membership renewal. Hence, there is a possibility of adverse selection with regard to CBHI enrollment and membership renewal in the study area. The third study revealed that CBHI enrollment is positively associated with adult outpatient use, inpatient care, and sick children health services visits. CBHI membership shows 0.50 (50%), 0.22 (22%), and 0.44 (44%) points higher probability of health service visits for adult outpatient, inpatient, and sick children’s health problem in the study area, respectively. Conclusion and recommendation: The study results in this thesis demonstrated important factors affecting CBHI enrollment and membership renewal. Moreover, it also revealed the link between CBHI enrollment and health service utilization. Therefore, multifaceted policy interventions need to be considered before the nationwide rollout of CBHI and implementation of Social Health Insurance (SHI) in Ethiopia. Strategies such as compulsory enrollment, differential premiums, and group enrollment are essential to tackle adverse selection. Provision of continuous education and social marketing activities to increase enrollment and maintain the sustainability of the schemes are crucial. Policy interventions that enhance the capacity of health facilities and CBHI schemes to provide the promised services to the members and build trust are also necessary. Benefit package expansion and other supply-side interventions are required to strengthen the positive effect of CBHI on health care utilization. Keywords: Adverse selection, Bivariate probit model, CBHI enrollment, Ethiopia, Health care use, Institutional trust, Membership renewal, Mixed-effect model, Mixed method Student number: 2014-31499

Forensics analysis on JPEG images : carving and forgery detection

Atnafu, Ayalneh Dessalegn Korea University 2016 국내박사

This dissertation covers issues in multimedia forensics, in particular it focuses on file carving and forgery detection on JPEG. The popularity of JPEG image in a wide area of applications makes it one of forensically important file formats. Forgery detection and recovery of JPEG images from an electronic device that is related to an investigation are the main objectives of multimedia forensics. File carving of fragmented files is a complicated process that requires specialized effort compared to the traditional file recovery techniques. The problem even gets harder if the fragments are corrupted and interdependent for complete decoding of the file. In JPEG file, the first fragment contains important header information that is critical to decode the image. Huffman table, quantization table, color information and dimension of the image are the main parameters. In previous papers, it is assumed that header information of the image like Huffman table, Reset (RST) value and Quantization table were readily available for the techniques to work. The proposed method extracts the width of the fragment from quantized AC coefficients of neighbouring Discrete Cosine Transform (DCT) blocks. There for the proposed method has reduce the assumptions to one parameter, Huffman table. Our method is able to estimate the width of test images that are used in previous papers correctly. Such early estimation of width information benefits forensic analysis of digital image evidences. The second part of this dissertation focuses on passive forgery detection. In digital forensics there are passive and active ways of detecting forgery. Although passive techniques are less effective compared to active ones, they are more usable. Passive forgery detection methods can be further classified into visible and invisible feature based detection methods. In this dissertation, Block Artifact Grid (BAG) based passive forgery detection of copy paste forgery on JPEG image is improved. BAG is one of invisible features that can be used to detect copy paste forgery. In previous methods the grid effect is computed using L_2 norm based functions. Such methods are effective for images with less outliers in DCT coefficients. However, complex images have many nonzero high frequency DCT coefficients which bias the output of L_2 norm based Local Effect (LE) computation. In this dissertation L_1 and L_0 norm based LE computation methods are introduced that suppresses the effect of outliers. The complete algorithm to detect copy paste forgery is provided with optional L_2, L_1 and L_0 norm based LE computation. The experimental result shows that the L_0 norm based approach has a much better performance with all test images. In addition to improving BAG based passive forgery detection, a hybrid bride forgery detection algorithm that combines visible and invisible feature based methods is introduced. Each visual and invisible feature based methods have their own merits and demerits. The proposed hybrid algorithm benefits from the merits of both individual methods, while it produces more information about the forgery.

Assessment of Household Solid Waste Management Practice in Addis Ababa, Ethiopia

Dessalegn Atnafu Goshu 경희대학교 대학원 2021 국내석사

This study is an assessment of household solid waste management practice in Addis Ababa, Ethiopia. This study focuses on factors that influence the practice of household solid waste management such as sorting, reuse and recycle practices. In this study primary and secondary data were used. The objective of this study is to assess household solid waste management practices and identify the influential factors and attitude of households with regard to their solid waste management practices and to improve the status of municipal solid waste management in Addis Ababa. In this research, a survey method was implemented to identify the factors and difficulties that influence the household practices and attitudes. The study revealed that the majority of households had a positive attitude toward solid waste management practices and had begun solid waste sorting, reuse and recycling practices which are favorable inputs for improving household practices in reuse, recycling and trash separation. However, the lack of strong laws and regulations and their enforcement, unstable service, poor coordination, lack of knowledge and financial constraints have proven to be highly influential issues while the lack of land, equipment and initiation are moderately influential factors in household practices in solid waste management. Poor coordination, lack of awareness, initiation, land and equipment are all associated with proper solid waste management practices such as solid waste sorting, reuse and recycling activities; therefore, recommendations to overcome these barriers are proposed at the end of this study.

Comparative analysis of codon optimization tools : advancing toward a multi-criteria framework for synthetic gene design

Demissie, Eden Atnafu Sungkyunkwan University 2025 국내석사

Codon optimization is an essential technique in synthetic biology and biopharmaceutical production, enhancing recombinant protein expression by fine-tuning genetic sequences to match the translational machinery and codon usage preferences of specific host organisms. This study presents a comprehensive comparative analysis of widely used codon optimization tools, focusing on their capacity to reflect host-specific codon biases, design principles, and parameters. Industrially relevant target proteins were evaluated in E. coli, S. cerevisiae, and CHO cells, uncovering significant variability in sequence design and clustering patterns across tools. Tools such as JCat, OPTIMIZER, ATGme, and GeneOptimizer demonstrated strong alignment with genome-wide and highly expressed gene-level codon usage, achieving high codon adaptation index (CAI) values and efficient codon-pair utilization. Conversely, tools like TISIGNER and IDT employed different optimization strategies that frequently produced divergent results. Other key parameters, including GC content, mRNA secondary structure stability (ΔG), and codon-pair bias (CPB), were analyzed to elucidate their influence on translational efficiency. While increased GC content enhanced mRNA stability in E. coli, A/T-rich codons in S. cerevisiae minimized secondary structure formation, and moderate GC content in CHO cells balanced mRNA stability and translation efficiency. Our findings highlight the limitations of single-metric approaches and advocate for a multi-criteria framework that integrates CAI, GC content, mRNA folding energy, and codon-pair considerations. This integrative strategy enables the design of tailored genetic sequences that meet host-specific requirements, advancing synthetic gene design for biotechnological innovation and precision biopharmaceutical applications. 코돈 최적화는 합성 생물학 및 생물약학 생산에 필수적인 기술로, 유전자 서열을 미세 조정하여 특정 숙주 유기체의 번역 기계 및 코돈 사용 선호도와 일치시켜 재조합 단백질 발현을 향상시킵니다. 이 연구는 널리 사용되는 코돈 최적화 도구에 대한 포괄적인 비교 분석을 제시하며, 숙주 특정 코돈 편향, 설계 원칙 및 매개변수를 반영하는 능력에 초점을 맞춥니다. 산업적으로 관련성 있는 표적 단백질은 E. coli, S. cerevisiae 및 CHO 세포에서 평가되었으며, 도구 간에 서열 설계 및 클러스터링 패턴에서 상당한 가변성을 발견했습니다. JCat, OPTIMIZER, ATGme 및 GeneOptimizer와 같은 도구는 게놈 전체 및 고도로 발현되는 유전자 수준 코돈 사용과 강력한 일치를 보여 높은 코돈 적응 지수(CAI) 값과 효율적인 코돈 쌍 활용을 달성했습니다. 반대로 TISIGNER 및 IDT와 같은 도구는 종종 다른 결과를 생성하는 다양한 최적화 전략을 사용했습니다. GC 함량, mRNA 2차 구조 안정성(ΔG), 코돈 쌍 편향(CPB)을 포함한 다른 주요 매개변수를 분석하여 번역 효율성에 미치는 영향을 설명했습니다. 증가된 GC 함량은 E. coli에서 mRNA 안정성을 향상시킨 반면, S. cerevisiae에서 A/T가 풍부한 코돈은 2차 구조 형성을 최소화했으며, CHO 세포에서 적당한 GC 함량은 mRNA 안정성과 번역 효율성을 균형 있게 조절했습니다. 우리의 연구 결과는 단일 측정 접근 방식의 한계를 강조하고 CAI, GC 함량, mRNA 폴딩 에너지, 코돈 쌍 고려 사항을 통합하는 다중 기준 프레임워크를 옹호합니다. 이 통합 전략을 통해 숙주 특정 요구 사항을 충족하는 맞춤형 유전자 시퀀스를 설계하여 생명공학 혁신과 정밀 생물약학 응용 분야를 위한 합성 유전자 설계를 발전시킬 수 있습니다.