국가필수예방접종 전액지원사업 후 예방접종현황의 변화 및 이용자 만족도 : 서울시 강남구 사례를 중심으로

이경희 고려대학교 보건대학원 2011 국내석사

Abstract Changes in Vaccination Status and User Satisfaction for the Full Coverage Project of the National Immunization Program(NIP) - Focus on Gangnam-Gu, Seoul- Kyung Hee Lee Department of Epidemiology and Health Informatics Graduate School of Public Health, Korea University (Supervising Professor : Byung-Chul Chun, M.D., MPH, Ph.D.) Objectives : The purpose of this study was to secure basic data for healthcare policy to improve immunization services by analyzing the changes in vaccination status and satisfaction on the Full Coverage Project of the National Immunization Program(NIP) from nongovernmental medical institutions and users in Gangnam-gu, Seoul, Republic of Korea. Methods : We compared the cost reimbursement requests for the expansion of NIP coverage and the Full Coverage Program, respectively, in the NIP in Gangnam-gu during from March to December in 2009. We compared total immunization registration, individual immunization registration, the immunization proportion ratio of public health centers, and the immunization rate regarding the hange of immunization status in 2008 vs. 2009 and the second half of 2008 vs. the second half of 2009, and surveyed nongovernmental medical institutions and users regarding service satisfaction and improvement. Results : The volume of reimbursement requests increased three to five times compared to before the Full Coverage Project of the NIP was adopted. Immunization registration increased 56.4% in this area compared with that in 2008. A total of 61,356 cases supported financially by the NIP in 2009 increased to 109.8 % compared with 29,246 cases that were not supported in 2008. The greatest increase in the number of vaccinations was for the DTaP vaccine whose rate was 192.8%, and the lowest was for th BCG vaccine at 34.8%. The immunization proportion ratio decreased from 18.9% in 2008 to 15.0% in 2009. The NIP immunization rate increased in Gangnam-gu from 56.3% in 2008 increased to 78.1% in 2009. The satisfaction for this project was 76.1% at nongovernmental medical institutions and 82.3% for users. Conclusion : The Full Coverage project of the NIP positively influenced the increase in immunization rate and immunization registration and the reduction in the public health center immunization proportion ratio and improved the quality of public health services by redefinining the partnership between public and nongovernmental medical institutions. Key words : National Immunization Program(NIP), expansion of NIP coverage, full Coverage of the NIP, immunization registration, immunization proportion ratio, immunization rate

영·유아 백신 접종의 특성 및 의료 접근성이 접종률에 미치는 영향

양유진 서울대학교 대학원 2017 국내석사

Immunization is one of the world’s most effective and cost-effective tools against the treat of emerging diseases. It is a fundamental strategy to achieve other health priorities and provide a platform for public health care improvement with powerful impact on social and economic development. To secure high level of vaccination rate is the key factor for evaluation of the success. The infant vaccination rate in Korea is recognized relatively high but still the gap between type of vaccines and regions. Thereby, continuous efforts with strategy of stakeholders are required also in Korea. The representative program of government is NIP(National Immunization Program) which was rolled out in 2009 supporting partial fee for infant vaccination. As of the year, vaccination rate showed increasing trend. Based on previous studies’ result, the change could be come from various factors influencing to vaccination simultaneously. And the study analyzing regional level of vaccination is not enough in Korea. So the objective of this study was to analyze which factors impact to the regional level of infant vaccination rate and the size of the impact and propose policies which be worth consideration in the future vaccination strategy. The data analyzed was ‘National vaccination rate report’ sample survey conducted in 2012, 2013 as a project of Korea CDC. Independent variables were comprised of two categories ‘Vaccination specific characteristics’ and ‘Health care accessibility’. The all independent variables of vaccination specific characteristics category showed impact to the ‘vaccination rate’ with statistical significance. Amongst the variables from health care accessibility, only the variable, number of public healthcare center per infants, influenced to ‘vaccination rate. The factors which showed impact to the first and the last vaccination was mandatory vaccine or not and fee for vaccination. The age and the number of simultaneous shots influenced to ‘first vaccination’ statistically significant but not to ‘last vaccination’. In case of vaccination rate of mandatory & the other vaccines, the fee, age and the term affected both of the rates. Whereas, number of simultaneous shots showed impact only to the mandatory vaccination rate and the number of public healthcare center per infants influence only to the other vaccines’ vaccination rate. The result proved that some part of the factors reported in preceding researches in Korea and other countries also affect as influencing factors to regional infant vaccination rate in Korea. The study result showed that multiple factors are influencing to the each type of immunization rate with different impact power. Referring to the result of this analysis, some suggestions for vaccination program could be proposed. Because financial burden to the parents has high impact at the decision for vaccination, the government should consider sustainable support on fee for vaccination such as NIP and expansion of the coverage of the program. In parallel, to prevent the cases that the financial problem itself to be a decision barrier in starting vaccination especially for optional vaccination, the health care professionals (doctors and nurses) should take more efforts to explain the benefits of vaccination with sufficient information. And the sustainable political focus, support and communication from government side on this area including the market price of optional vaccines could be required as well. Considering the current vaccination behavior in Korea, the discussion reducing infants’ physical burden and parents’ psychological burden induced by lots of simultaneous vaccination shots also should be held by government continuously.

의료급여가구 영유아의 예방접종률과 관련요인 분석 : 대도시 일개구를 중심으로

이현승 연세대학교 보건대학원 2004 국내석사

The purpose of this study is (1) to grasp the performance levels of state immunization through the examination of (i) immunization rate, (ii) timely immunization rate, and (iii) three-stage complete immunization rate of children receiving medical Assistance in large cities and (2) to present different means of increasing low-income household immunization rates and to suggest various avenues of improving government-funded free vaccination program. Over periods extending from May 3rd through 8th of 2004 and from May 23th through 30th of the same year, the interviews were conducted to 88 children under the age of 24 months who were residing in Incheon Metropolitan City and receiving medical assistance. In the analysis of immunization related-factors, Chi-square test was adopted and by using the BCG-Hepatitis B vaccine-DPT-Polio complete immunization rate as a dependent variable, the study examines the differences in complete immunization rate according to the studied immunization related-factors. The results are as follows;1.As reasons of delayed or ommitted to get vaccinations, 38.6% of the interviewee responded 'illnesses of a child', 22.8% answered 'just forgot to get one', and 20.2% replied 'lack of money'. 2. As reasons for using the public health centers, 54.9% responded 'low cost', 22.0% answered 'trust', and as reasons for using private medical centers, 36.7% replied 'the convenient location', 33.3% answered 'familiar through visits for other illnesses'. 3.The rates of getting vaccination at the public medical centers varied according to the kind of a vaccination. In case of the BCG vaccine, the rate marked 30.0%, as for the Hepatitis B vaccine, the rate marked 11.9%, 45.0%, 59.1% (in order of the 1st, 2nd, and the 3rd vaccination), as to the DPT-Polio vaccine, the rate marked 55.0%, 59.4%, 60.7%(in order of the 1st, 2nd, and the 3rd vaccination), and in case of the MMR vaccine, the rate reached 64.7%. 4. The percentage of possessing a vaccination schedule book was 94.3%.5.Concerning the immunization rate, the BCG vaccine reached 95.2%, the Hepatitis B vaccine marked 100.0%, 97.6%, 90.0%(in order of the 1st, 2nd, and the 3rd vaccination), the DPT-Polio vaccine rated 97.5%, 87.7%, 87.1% respectively(in order of the 1st, 2nd, and the 3rd vaccination), and the MMR vaccine marked 83.3%.6. Regarding the timely immunization rate, the BCG vaccine rated 61.0%, the DPT-Polio vaccine marked 87.7%, 78.1%, 74.3%(in order of the 1st, 2nd, and the 3rd vaccination), and the MMR vaccine reached 61.1%.7. As to the complete immunization rate, as defined the percentage of children who recieved three doses of Hepatitis B vaccine and DPT-Polio vaccine, rated 90.0% and 85.7% respectively.8.The BCG-Hepatitis B vaccine-DPT-Polio complete immunization rate of the group of less than 20 minute-distances from the public health centers turned out to be 96.67%. Meanwhile, the BCG-Hepatitis B vaccine-DPT-Polio complete immunization rate of the group of over 20 minute-distances recorded 76.92%, which is statistically meaningful(P<0.05). The immunization rates of the children with medical assistance were lower than the results of the whole population in preceding studies. Despite the removal of financial barriers through free services provided at the public health centers, the main reasons behind lower immunization rates were (1) the inconvenient and far locations of the public health center and (2) the financial costs of vaccinations incurred in case of private medical clinic use. Such barriers arising from demographic barriers of public health center use and financial burdens from private medical clinic use means can be attributed to the fact that free services provided by the government are limited only to the public health centers. Therefore, the government must explore different means of expanding the free services to the private sector in order to adequately and timely provide its services of free vaccinations. 이 연구의 목적은 대도시 의료급여가구 영유아의 예방접종률, 적기접종률, 완전접종률 조사를 통해 예방접종 이행실태를 파악하고, 예방접종 관련요인을 분석하여 저소득층의 예방접종률 향상방안과 국가 무료예방접종사업의 개선방향을 제시하는 것이다. 이 연구는 2004년 5월 3일부터 8일까지와 동월 23일부터 30일까지 2차에 걸쳐 총 12일간, 인천광역시 4개구 24개월 미만의 의료급여가구 영유아 127명 중 88명을 대상으로 면담조사를 통해 이루어졌다. 예방접종 관련요인 분석은 BCG-B형간염-DPT-Polio 완전접종률을 종속변수로 선정하고, 관련요인에 따른 완전접종률의 차이를 카이제곱검사로 검정하였다. 의료급여가구 영유아의 예방접종 이행실태 설문결과, 예방접종의 누락 및 지연 사유로 “아이의 질환”이 38.6%, “깜박 잊어버려서“가 22.8%, ”돈이 없어서“가 20.2%순이었다. 접종기관 선택이유에 대하여 보건소를 이용하는 이유로 ”비용저렴”이 54.9%, “신뢰감”이 22.0%순이었고, 민간의료기관을 이용하는 이유로 “이용이 편리한 위치“가 36.7%, ”질병으로 평상시 이용“이 33.3%순이었다. 접종기관 분포는 보건소에서 접종받는 비율이 BCG는 30.0%, B형간염 1차, 2차, 3차는 각각 11.9%, 45.0%, 59.1%, DPT-Polio 1차, 2차, 3차는 각각 55.0%, 59.4%, 60.7%, MMR은 64.7%이었다. 예방접종 수첩보유율은 94.3%이었다. 예방접종률은 BCG가 95.2%, B형간염 1차, 2차, 3차는 각각 100.0%, 97.6%, 90.0%, DPT-Polio 1차, 2차, 3차는 각각 97.5%, 87.7%, 87.1%이었고, MMR은 83.3%이었다. 적기접종률은 BCG가 61.0%, DPT-Polio 1차, 2차, 3차는 각각 87.7%, 78.1%, 74.3%, MMR은 61.1%이었다. B형간염과 DPT-Polio 3회 완전접종률은 각각 90.0%와 85.7%이었다. 예방접종 관련요인 분석결과, 거주지에서 보건소까지의 도달시간이 “20분 이하”인 군의 BCG-B형간염-DPT-Polio 완전접종률은 96.67%인 반면, “20분 초과”인 군의 BCG-B형간염-DPT-Polio 완전접종률은 76.92%로, 거주지에서 보건소까지의 도달시간이 “20분 초과”인 군에서 BCG-B형간염-DPT-Polio 완전접종률이 낮았고 이는 통계적으로 유의하였다(P<0.05). 이번 연구에서 의료급여가구 영유아의 예방접종률과 적기접종률은 전 계층을 대상으로 조사된 선행연구결과들과 비교해 낮았다. 보건소 무료예방접종사업으로 재정적 장애요인이 제거되었음에도 불구하고 의료급여가구 영유아의 예방접종률과 적기접종률이 낮은 이유는, 이번 연구 결과에서 알 수 있듯이, 보건소가 거주지에서 멀리 떨어진 경우 이동상의 어려움으로 보건소 이용이 제한을 받게 되고, 민간의료기관을 이용할 경우 본인이 부담해야하는 접종비용으로 인해 민간의료기관 이용이 제한을 받기 때문이다. 이러한 보건소 이용시의 지리적 접근성의 차이와 민간의료기관 이용시의 재정적 부담이 발생하는 원인은 무료접종기관을 보건소에 국한시킨 현행 보건소 중심의 무료예방접종사업에서 기인한다. 따라서 어느 영유아나 접종기관 이용에 장애를 받지 않고 적기에 적절한 예방접종이 이루어지기 위해서는 국가 무료예방접종사업의 범위를 민간의료기관으로 확대하는 방안이 추진되어야 할 것이다.

Pharmacists as Immunizes: Increasing Non-Influenza Adult Immunization Rates

Plumly, Kimberly Mace ProQuest Dissertations & Theses Drew University 2020 해외박사(DDOD)

Immune cell analysis of immune-check point inhibitor treated patients

김혜련 동아대학교 대학원 2022 국내박사

세포 생물학과 면역학의 발달로, 표적 치료제, 단일클론 항체, 그리고 면역관문억제제가 암 치료에 사용되고 있다. 일부 환자들은 면역관문억제제의 혜택을 받지만, 다른 환자들은 면역관문억제제에 반응하지 않거나 급성 진행으로 고통받는다. 과거부터 면역관문억제제의 효능을 예측할 수 있는 생체 표지자를 찾는 노력이 계속되어왔으나, 불행하게도 아직까지 인정받은 생체 표지자는 없는 상태이다. 이에 말초혈액을 이용하여 면역관문억제제의 효능을 예측할 수 있는 생체 표지자를 찾기 위해 본 연구를 계획하였다. 총 182명의 성인 환자를 대상으로 하였으며, 고형암 또는 호지킨 림프종에 대해 면역관문억제제 (pembrolizumab, nivolumab, atezolizumab, 또는 durvalumab) 치료를 받기로 예정된 성인 환자를 연구의 대상으로 하였으며, 이전에 면역관문억제제에 노출이 있었던 환자는 제외하였다. 말초혈액은 면역관문억제제 사용 전후에 채혈을 하여 각 환자에서의 면역세포 분율의 변화를 분석하였다. 면역세포는 panel 1과 panel 2로 나누어서 분석하였으며, 면역세포 분율의 변화와 반응률, 생존기간 사이의 통계성 유의성을 분석하였다. 최종적으로 90명의 환자에서 panel 1, panel 2 면역세포 분석을 시행하였다. 중위 연령은 65세 (범위, 26-84) 였으며, 폐암이 가장 많고 (50.0%, n=45), 그 다음으로는 담도암 (7.8%, n=7), 간세포암 (6.7%, n=6)이 그 뒤를 이었다. 중위 추적 관찰 기간은 4.63개월 (사분위간 범위, 2.03-8.87) 이었으며, 중위 치료 기간은 2.40개월 (사분위간 범위, 1.31-5.53) 이었다. 90명의 환자에서 완전 관해를 획득한 환자는 없었으며, 객관 반응률은 14.4% (n=13), 질병 통제율은 50.0% (n=45) 였다. 중위 무진행 생존기간은 6.00 months (95% CI, 3.11-8.89), 중위 전반적 생존기간은 13.90 months (95% CI, 5.62-22.19) 였다. NKp46-/CD56+ NK cell 분율이 증가한 환자에서 객관 반응률이 통계학적으로 유의미하게 높았으며 (22.0% 대 5.0%, p=0.033), 전반적 생존기간 역시 유의미하기 길었다 (16.77 개월 대 7.47 개월, p=0.013). NKp46-/CD56+ NK cell 분율이 증가한 환자에서 무진행 생존기간이 긴 경향을 보였으나 (6.97 개월 대 3.30 개월), p=0.050으로 통계학적으로 유의미하지 않았다. 결론적으로, 면역관문억제제 사용 전후의 면역세포 분율의 변화가 면역관문억제제 효과를 예측할 수 있는 새로운 생물 표지자로 사용될 수 있을 것으로 기대된다.

Engineering a Robust and Scalable Platforn for the Production of IEILC1-Like Nk Cells, a Novel Solid Tumor Immunothereapeutic Modality

Horowitz, Nina Beryl ProQuest Dissertations & Theses Stanford Universit 2022 해외박사(DDOD)

While surgery, radiation, and chemotherapy have been the gold standards of cancer treatment for decades, they are severely limited in certain aspects -- not all tumors are operable, and chemotherapy and radiotherapy can damage healthy tissues as well as the cancer cells. Targeted therapy and immunotherapy were hailed as solutions to this, but they also have drawbacks of their own. The first is that they can be extremely expensive, which leads to financial toxicity, and the second is that they can sometimes cause cytotoxicity to healthy tissues or even occasionally kill the patients they are meant to treat. Natural killer (NK) cell-based therapies solve both issues as they exhibit an optimal safety profile and can be given off-the-shelf to lower the cost of production, but their success has been mostly restricted to liquid tumors.Solid tumors account for 90% of all cancer diagnoses and are significantly more difficult to treat due to a variety of factors such as tumor heterogeneity, the immunosuppressive tumor microenvironment (TME), and poor immune cell trafficking. Here, I present our work designing NK cells with optimized functionalities for solid tumor indications. We have previously identified a novel population of NK cells within head and neck squamous cell carcinoma (SCC) patients that maintain an activated and highly proliferative phenotype within the TME and resemble intraepithelial group 1 innate lymphoid cells (ieILC1s) due to their expression of CD49a and CD103. In earlier work, we were able to induce moderate levels of CD49a and CD103 expression on peripheral blood NK cells through injection of the NK cells into subcutaneous tumors or co-culture with live tumor cells -- but these cells were not thoroughly studied in vitro or in vitro, and this functional evaluation is critical for designing solid tumor therapeutics.We designed cell culture systems that can reliably differentiate peripheral blood NK cells into highly pure, clinically relevant doses of ieILC1-like NK cells. This platform design involved comparing media conditions, cytokine exposure, feeder cell ratios, seeding density, and many other variables. We then assessed the ability of these ieILC1-like NK cells to kill target cells, produce inflammatory cytokines, interact with tumor-targeting antibodies and chimeric antigen receptors, and infiltrate solid tumors. Our results show that ieILC1-like NK cells exhibit high cytotoxicity, high production of cytokines, and tumor infiltration rates up to ten times higher than other NK cell products that are currently being tested in the clinic. This cytotoxicity can be enhanced by using antibodies or chimeric antigen receptors in manners similar to conventional NK cells. Furthermore, we established the role of the surface integrin CD103 as a critical molecular regulator of tumor invasion by NK cells. This work represents an important step forward in the design of affordable and accessible cell therapeutics for solid tumors.

한국 채권시장에서 면역전략의 유용성에 관한 연구

이상인 연세대학교 경제대학원 2003 국내석사

한국 자본시장은 1997년 외환위기 이후에 많은 변화를 경험하였다. 우선 채권시장을 포함한 자본시장은 IMF관리 계획 아래 전반적인 자본시장제도, 시장하부구조, 시장참가자, 그리고 자산가격결정 등에 있어서 국제적인 표준에 맞게 크게 개선되었다. 국내 기관투자가나 개인 투자자들은 이제 본격적으로 선진투자기법으로 무장한 외국투자자들과 한국자본시장에서 경쟁하게 되었다. 이러한 과정에서 국내투자자들은 과거와 달리 투자행태에 있어서 주요한 변화를 보이고 있다. 즉 종전에 수익성 위주의 투자행태에서 위험과 수익을 동시에 고려한 투자의사 결정이 이루어지고 있다. 특히 채권시장에서도 개인투자가나 채권 포트폴리오 관리자들은 채권을 매입하여 투자기간동안 보유하는 만기보유에서, 투자시점에서 설정한 목표수익률을 달성하기 위하여 소극적인 투자전략과 함께 적극적인 투자전략을 실행하고 있다. 이러한 기관투자가의 투자행태의 변화는 개인투자자의 다양한 요구에 부합하는 결과이며, 나아가 적극적으로 채권투자전략을 연구, 개발하여 선진 투자기관들과 경쟁할 수 있는 금융 신상품의 개발도 절실하게 요구되고 있다. 따라서 본 연구는 국내 자본시장에서 주식시장과 달리 상대적으로 연구가 미진하였던 채권투자전략에 대해 연구해보고, 그 중에서도 채권투자전략의 가장 기초가 되는 채권면역전략을 국내 적용하여 그 결과를 실증 분석해 보았다. 채권 포트폴리오 관리자는 채권 포트폴리오를 관리할 때 여러 가지 위험 중에서 투자기간 동안에 이자율이 변동하여도 목표수익률을 어떻게 달성하느냐에 지대한 관심을 가지고 있다. 이자율이 어떻게 변하여도 궁극적으로 목표수익률을 달성하는 채권투자전략으로는 가중평균만기(duration)를 이용한 채권면역전략 (bond immunization strategy)이 있다. 이 전략은 목표투자기간과 채권 포트폴리오의 가중평균만기를 일치시킴으로써 가능하다. 채권의 특성상 이자율이 상승하면 채권가격은 하락하지만 미래에 발생하는 이자 금액의 재투자수익은 증가한다. 반대로 이자율이 하락하면 채권가격은 상승하지만 재투자수익은 감소한다. 이렇게 이자율이 변동하는 경우 가격변동위험과 재투자위험은 서로 상반된 효과를 가지고 있으므로 이를 이용한 투자전략이 가중평균만기를 이용한 면역전략의 핵심 내용이다. 한국채권시장에서도 채권면역전략의 유용성이 입증된다면 침체되어 있는 채권형 펀드 상품개발에 활력을 불어 넣을 수 있고 나아가 국내 채권시장의 효율성도 어느 정도 가늠해 볼 수 있다. 이 점에 착안하여 한국채권시장에서 2000년 이후 자료를 이용하여 실증분석을 실시하였다. 채권면역전략의 한계점과 실증분석의 한계점에도 불구하고 연구결과를 요약하면 다음과 같다. 첫째, 연구 대상기간 동안 실증 분석한 결과 실현수익률 면에서는 채권면역전략, 만기일치전략 그리고 롤오버전략의 순으로 나타났다. 하지만 채권면역전략과 만기일치전략은 목표수익률을 초과 달성하였지만 롤오버전략은 목표수익률에 미달하였다. 둘째, 실현수익률의 표준편차는 롤오버전략, 만기일치전략 그리고 채권면역전략의 순으로 작게 나타났고 만기일치전략과 채권면역전략의 표준편차의 차이는 0.06%로 나타났다. 셋째, 기간별 목표수익률과 실현수익률 차이의 표준편자는 만기일치전략, 채권면역전략 그리고 롤오버전략의 순으로 작게 나타났다. 넷째, 만기일치전략과 채권면역전략의 양자 택일을 위하여 가설을 검증한 결과 채권면역전략이 우월한 것으로 검정 되었다. 이상과 같은 실증분석 결과는 다음 두 가지 요인에 영향을 받은 것으로 판단된다. 하나는 연구 대상기간 동안 시장금리가 지속적으로 하락 하였다. 그리고 수익률곡선이 우 상향하는 모양을 유지하여 잔존기간이 짧을수록 수익률의 하락세는 지속되었다. 또 다른 요인은 포트폴리오 구성 시점에 편입된 채권의 표면금리가 편입수익률보다 낮았다. 이것은 만기일치전략과 채권면역전략의 가정에서 차이가 난다. 즉 금리 하향기에 채권면역전략은 가중평균만기와 목표투자기간을 일치시키고 6개월마다 재조정함으로써 만기일치전략에 편입된 채권보다 면역전략에 편입된 채권의 만기가 더 길기 때문에 투자수익률이 높게 실현된 것으로 분석 되었다. 하지만 채권면역전략에 대한 선행 연구 결과에 의하면 금리 상승기에도 유용성 입증되었다. 이상의 결과를 종합하면 분석 기간이 짧고, 이용 가능한 실증자료가 빈약하다는 한계점에도 불구하고 한국 채권시장에서 채권면역전략이 유용하다는 결론을 내릴 수 있었다. 따라서 채권 포트폴리오 관리자들은 채권면역전략을 적극적으로 활용할 수 있으며, 한국 채권시장에서 이를 토대로 다양한 투자기법을 개발하여 실제 채권형 펀드에 적용할 수 있다는 판단이다. Korean capital market including bond market has experienced a number of changes after foreign currency crisis in 1997. It has improved the trading rules, trading customs and market infrastructure to cope with global standard under IMF programs. One of the meaningful changes is that participants in capital markets start to place investment risk ahead of return from securities. This change in investment behavior resulted from the bankruptcy of some local banks as well as insolvency of large conglomerates in 1997 that had never happened before in local market. This study aims at testing and verifying the usefulness of immunization strategy in Korea bond market that is one of the most important investment strategies. Bonds may generally expose an investor to one or more of the following risks such as interest-rate risk, reinvestment risk, default risk, inflation risk, and call risk. Among these risks, interest-rate risk is by far major risk faced by investor in bond market. The others can be removed from diversification of bonds. Concerning the interest-rate risk, bonds have price risk and reinvestment risk when interest-rate changes. These two risks have trade-off relationship. To take advantage of trade-off effect between price risk and reinvestment risk, bond portfolio manager can avoid the risks by using the concept of bond duration introduced by F.R Macaulay. A strategy based on these offsetting effects is called immunization. Is the Bond immunization strategy feasible in Korea bond market? If it is feasible, it is able to guarantee promised yield regardless of any interest rate change for the planning period. In order to test and verify the immunization strategy in Korea bond market, we need some assumptions as follow: First, 10 bond portfolios consisted of corporate bonds with six-month coupon was constructed from Jan.2000 to Oct. 2000 by each month. All funds were invested in bonds as a bullet type at the initial investment times. The planning period was two years. Second, the target or promised yields of each fund were the monthly average market rates at the time of establishing funds. The Market rates of corporate bond by KSDA (Korea Securities Dealers Association) were applied for the valuation of portfolios to count realized yields every six-month. Third, maturity matching strategy and rollover strategy were implemented to each portfolio to compare and analyze the results of immunization strategy. Maturity strategy was to buy bonds with maturity to the end of planning period at the time of investment. In addition, coupon and repayment from bonds were reinvested in the same bonds subsequently. Rollover strategy was to invest in 1-year bonds and then repayment as well as coupon was rolled over to the same bonds. On the other hands, immunization strategy was implemented by matching portfolio duration to planning period. The duration of each portfolio was rebalanced every six month at market rate. The empirical results present as follows: The realized yields of both Immunization strategy and maturity strategy exceeded the promised yields for all planning periods, but the yield of rollover strategy did not. Immunization strategy was superior to maturity strategy by testing the statistics such standard deviation, t-test. These results might be derived from two factors. The one is the continuous downward trend of market rate for the objective period. The other is that coupon rate was lower than market rate at the beginning of planning periods. Although this study has some constraints and assumptions, it is empirically verified that immunization strategy is feasible and useful to achieve promised yields under any interestrate fluctuation. Furthermore, it is to conclude indirectly that Korea bond market has become efficient in terms of term structure of interest rate for the recent years.

Design of analog front-end of touch-screen controller with enhanced noise immunity and configurable SNR and frame rate

박준은 Seoul National University 2017 국내박사

A design of analog front-end (AFE) for touch-screen controller (TSC) with highly enhanced noise immunity and configurable signal-to-noise ratio (SNR) and frame rate is proposed. First, the AFE for the mobile TSC is presented, which provides a configurable SNR and frame rate. The AFE configures its SNR and frame rate by adjusting the sampling cycles of the employed ADC. The test chip is fabricated in a 0.18-μm CMOS process and occupies a 2.2-mm2 active area. The test chip achieves 60-dB SNR and 200-Hz frame rate with 12 × 8 TSP. The SNR can be adjusted from 40 to 67 dB, while the frame rate is then inversely scaled from 50 Hz to 6.4 kHz. The test chip consumes 6.26 mW from a 3.3-V supply. The AFE for the tablet TSC is also presented, which provides highly enhanced noise immunity and configurable SNR and frame rate. The proposed AFE provides TX channels of 36 and RX channels of 64 in order to support a large-size TSP. A multi-driving TX structure with frequency-hopping signal generator is employed to improve the SNR and noise immunity. For a suppression of severe noise interference injected through the TSP, the RX sensing block adopts pre-filtering differential sensing method and high-order noise filtering structure. The AFE supports configurable SNR and frame rate with on-chip frame-rate controller. The test chip is fabri-cated in a 0.18-μm CMOS process. The active area of the test chip is 36 mm2. A 12.2-inch TSP with TX channels of 36 and RX channels of 64 is used in the measurement. The test chip achieves 54-dB SNR and 120-Hz frame rate with a finger touch. The frame rate can be adjusted from 85 to 385 Hz. The test chip achieves up to 20-Vpp noise immunity. The test chip consumes 94.5 mW with a 3.3-V supply.

Cardiac Vagal Tone: Regulator of Inflammation and Clinical Symptoms in Insomnia and Schizophrenia

Reed, Alexandra Claire ProQuest Dissertations & Theses University of Cali 2021 해외박사(DDOD)