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Analog Predistortion High Power Amplifier Using Novel Low Memory Matching Topology
Jeonghyeon Cha,Sungchul Hong,Ildu Kim,Junghwan Moon,Jungjoon Kim,Bumman Kim,Jangheon Kim,Young Yun Woo 한국전자파학회JEES 2007 Journal of Electromagnetic Engineering and Science Vol.7 No.4
This paper represents an analog predistortion linearizer for the high power amplifier with low memory effect. The high power amplifier is implemented using a 90-W peak envelope power(PEP) LDMOSFET at 2.14-㎓ and an envelope short matching topology is applied at the active ports to minimize the memory effect. The analog predistortion circuit comprises the fundamental path and the cuber and quintic generating circuits, whose amplitudes and phases can be controlled independently. The predistortion circuit is tested for two-tone and wide-band code division multiple access(WCDMA) 4FA signals. For the WCDMA signal, the adjacent channel leakage ratios(ACLRs) at 5 ㎒ offset are improved by 12.4 ㏈ at average output powers of 36 dBm and 42 dBm.
김정현(Kim, Jeonghyeon),이상균(Lee, Sang-Gyun),이봉주(Lee, Bong Joo),김주옥(Kim, Joo ok),이청아(Lee, Cheong-ah),유조안(Yoo, Joan),김현수(Kim, Hyun-Soo) 한국아동복지학회 2022 한국아동복지학 Vol.71 No.1
이 연구는 아동학대 재발생과 관련하여 국내·외 선행연구 및 국가통계의 조작적 정의를 살펴보고, 여러 산출 방법의 특징 및 그 기준에 따른 재학대율을 비교하였다. 이 연구에서 적용한 재학대율 산출 기준은 다음과 같다. 첫째, 우리나라에서 아동학대 국가통계 산출을 위해 적용하는 동일 피해 아동에 대한 동일 행위자의 5년 내 재학대 여부, 둘째, 행위자에 대한 구분 없이 피해 아동 기준 5년 내 재학대 여부, 셋째, 최초 학대 보고 기준 1년 이내 재학대 발생이다. 비교 분석을 위해 2012년∼2020년 간 우리나라 국가아동학대정보시스템에 입력된 자료를 활용하였고, 데이터베이스 내 존재하는 오류를 살펴보고, 전처리 과정을 통해 최종 분석자료를 선정하였다. 분석 결과, 현행 동일 피해 아동/행위자 기준의 연도별 재학대율은 8.0%∼11.3%로 집계되었고, 피해 아동을 기준으로 재학대율을 산출한 결과는 11.5%∼21.7%로 약 2배 정도 차이가 나타나는 것으로 확인되었다. 발생한 차이에 대해 기준별 아동특성을 연령, 성별, 학대행위자와 피해아동과의 관계, 학대유형, 기초생활보장 수급 여부로 구분하여 살펴보았고, 산출 기준에 따른 결과 차이를 기술하였다. 한편, 동일 피해아동/행위자로 재학대율을 산출할 때는 부 혹은 모의 단독 재학대만 추정이 가능하고, 부와 모가 시간적 간격을 두고 학대한 경우는 재학대에서 제외되는 문제가 있다. 이에 대해 부모의 재학대 행위자군을 비교한 결과 부의 단독 재학대는 31.4%, 모의 단독 재학대는 22.1%, 부와 모로 이루어진 재학대는 38.4%로 부와 모로 이루어진 경우의 비율이 가장 높았다. 즉, 현재의 재학대 기준으로는 부 혹은 모의 단독 재학대에 개입을 요구하는 결과를 낳는 오류를 범할 수 있다. 따라서, 이 연구 결과를 바탕으로 아동학대 재발생에 대한 기준을 재정립할 것을 제언하고, 이를 근거로 한 아동보호서비스에 대한 실천적 논의를 제시하였다. This study examined the operational definitions of child maltreatment recurrence by reviewing Korean and foreign literature and national statistics. We compared the characteristics of various calculation methods and recurrence rates of child maltreatment according to their standards. In this study, the criteria for calculating recurrence rates of child maltreatment were (a) whether the same perpetrator has re-abused the same child within five years (applied in Korean national statistics on child abuse); (b) whether the child victim has been re-abused within five years, regardless of the perpetrator; and (c) whether child maltreatment recurs within one year of receipt of the initial report. For comparative analysis, we employed data of the Korean Child Protective Services (CPS) from 2012 to 2020, examined errors existing in the database, and selected the data for final analysis through a rigorous pre-processing process. The results of the analysis showed that the current child maltreatment recurrence rate for the same child victim/perpetrator was 8.0%-11.3% annually, and this rate based solely on the child victim was 11.5%-21.7%, approximately twice that of the same child victim/perpetrator. We examined differences in childrens characteristics across standards by age, gender, relationship to the perpetrator, type of abuse, and receipt of National Basic Likelihood Security, and we discussed these differences according to the calculation criteria. When calculating the recurrence rates of child maltreatment for the same child victim/perpetrator, we included the re-abuse rate only when it was a single perpetrator and either the childs father or mother. Thus, if the father and mother perpetrated the abuse at different intervals, this excluded them from the recurrence of child maltreatment. The results of the comparitive analysis of groups of parental perpetrators showed thatthe fathers re-abuse rate was 31.4%, that of the mother was 22.1%, and that of both parents was 38.4%. Our results indicate that there is a need to reconsider the definitions of child maltreatment recurrence and initiate a practical discussion on child protection services.
액체질소 직접분사 냉각방식 mRNA 백신 극저온 저장용기 제작
김기환(Kihwan kim),문정민(Jeongmin Mun),김한영(Hanyoung Kim),김유빈(Yubin Kim),백정현(Jeonghyeon Baek),김석호(Seokho Kim) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.05
In particular, as the mRNA vaccine becomes a major preventive vaccine in the case of COVID-19, the transportation method is being studied to meet global demand. For example, recently developed as a COVID-19 vaccine, Pfizer vaccines should be stored in the temperature range of -70℃, and similar vaccines should also be stored a -30 ℃ or below. However, existing cold storage systems are too high cost to apply storage systems below -30 ℃ and are difficult to apply in transportation. In this study, storage of direct injection using liquid nitrogen was manufactured and maintaining temperature of demanded target. In addition, vaccine storage containers were designed with considering thermal insulation, manufactured, and performance evaluations were implemented.
Contact Type Thread Tester for Tap Inspection Automation
Jeonghyeon Kim,Sangwon Choi,Jaekuk Choi,Dongsun Lim,Jonghoek Kim 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10
In this paper, we introduce a contact type thread tester which can automatically sort out bad thread holes. The existing non-contact type testers used eddy current, camera, ultrasonic, etc. However, non-contact type testers are vulnerable to noise. In this paper, a contact type inspection method is used to sort out the defects of the thread by measuring the reverse torque that occurs while tightening the bolt and threaded holes. This tester is insensitive to noise, such as vibration. We can inspect a thread hole regardless of the size of the hole. Also, the tester automatically aligns bolt and thread hole positions in order to remove the positional error. The tester checks the size of the thread hole using a camera, and automatically carries out the inspection with the optimum torque associated to the hole size. In addition, we develop a smartphone application to control the tester remotely.
( Jeonghyeon Im ),( Hee Young Kwon ),( In Kyoung Kim ),( Chang Dong Yeo ),( Sei Won Kim ),( Heayon Lee ),( Jung Won Heo ),( Sang Haak Lee ) 대한결핵 및 호흡기학회 2020 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.128 No.-
Purpose Hyperbaric oxygen therapy (HBO) to increase anticancer effect, despite several positive Results, has been suggested to have a toxicity problem in other tissues, so further studies on the conditions and application of oxygen therapy are needed. The purpose of this study is to evaluate the anticancer effect of paclitaxel (PTX) in lung cancer cells under normobaric oxygen exposure. Methods Non-small cell lung cancer (NSCLC) cell line A549 and the paclitaxel resistant cell line A549/PR were used. Cell viability, ability of migration and proliferation were evaluated in room air (RA) or normobaric oxygen (NBO) air condition for 48hs. The expression apoptosis related proteins was detected. For elucidation of the cell death in PTX treated A549/PR cells by NBO, the expression level of the C/EBP homologous protein (CHOP) and autophagy related proteins were analyzed. Results NBO exposure attenuated cell viability, ability of migration and proliferation ability in A549 cells and A549/PR cells therby increased apoptotic cell death by PTX. CHOP expression of A549/PR cells was increased by NBO exposure compare to RA condition. And conversion of LC3B-I to LC3B-II by PTX was reduced in A549 and A549/PR cells in NBO exposure (Figure 1-3). Conclusions Our Results show that NBO exposure synergistically increased the apoptotic cell death of A549 and A549/PR cells by paclitaxel. Also, cell death of A549/PR cells under NBO condition was induced by CHOP-mediated disregulation of autophagy. These findings suggest that the NBO exposure can promote the sensitivity of paclitaxel in lung cancer cells by CHOP activation and disregulation of autophagy.