Optical Charge Pumping Technique for Extracting Interface States of Nano-Scale SONOS Flash Memories

Lee Sunyeong,김대환,Choi Chang-Min,Jeon Ki-Chan,Kang Gu-Cheol,Kim Dong Myong,Kim Kwan-Young,Kim Se-Woon,Lee Jang-Uk,Lee Jong Duk,Park Jun-Hyun,박병국,Park So-Ra,Roh Kang-Seob,Seo Seung-Hwan,Shin Hyungcheol 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.III

The optical charge pumping (CP) technique is proposed as a simple and fast method for extracting the energy distribution of interface trap, $D_{it}$, of silicon-oxide-nitride-oxide-silicon (SONOS) flash memories. It is based on the optical response of a subthreshold slope of a SONOS memory cell transistor and is more effectively applicable to nano-scale emerging devices than the conventional CP technique, because no electrical pulse is required during extraction and because the current is measured not from the substrate, but from the drain contact. This means that a large gate current can be easily corrected by monitoring both the gate current and the drain current, no parasitic effect is caused by excluding the pulse measurement setup, and the extraction of $D_{it}$ in devices on silicon-on-insulator substrates is possible. The results applied to SONOS memories show that the generation rate of interface traps with program/erase cycles is higher in the NAND flash scheme rather than in the NOR flash scheme.

Radiation-induced changes in DNA methylation and their relationship to chromosome aberrations in nuclear power plant workers

Lee, Younghyun,Kim, Yang Jee,Choi, Young Joo,Lee, Joong Won,Lee, Sunyeong,Cho, Yoon Hee,Chung, Hai Won Informa Healthcare 2015 International Journal of Radiation Biology Vol.91 No.2

<P><I>Purpose</I>: We investigated the association between occupational radiation exposure and DNA methylation changes in nuclear power plant workers. We also evaluated whether radiation- induced DNA methylation alterations are associated with chromosome aberrations.</P><P><I>Materials and methods</I>: The study population included 170 radiation-exposed workers and 30 controls. We measured global, long interspersed nuclear element-1 (LINE-1), and satellite 2 methylation levels in blood leukocyte DNA. The analysis of chromosome aberrations was performed on peripheral lymphocytes.</P><P><I>Results</I>: Global DNA methylation levels were lower in radiation-exposed workers than in controls. The methylation levels were negatively associated with the recent 1.5-year radiation dose in a multiple linear regression model (β = − 0.0088, <I>p</I> ≤ 0.001); the levels increased proportionally with the total cumulative dose in radiation-exposed workers. LINE-1 methylation levels were higher in radiation-exposed workers than in controls and were significantly associated with the total cumulative radiation dose in a multiple linear regression model (β = − 0.031, <I>p</I> = 0.035). Global DNA methylation levels were also correlated with chromosome aberrations among workers. Workers with low global methylation levels had a higher frequency of chromosome aberrations than did subjects with high global methylation levels.</P><P><I>Conclusion</I>: Occupational exposure to low-dose radiation could affect DNA methylation levels, and the radiation-induced DNA methylation alterations may be associated with chromosome aberrations.</P>

Nonmonotonic Effects of Chronic Low-Dose Di(2-ethylhexyl) Phthalate on Gonadal Weight and Reproduction

Sunyeong Cha,Kayeon Jung,Min Young Lee,Yeon Jeong Hwang,Eunhyeok Yang,Sung-Ho Lee,Hyo-il Jung,Yong-Pil Cheon 한국발생생물학회 2018 발생과 생식 Vol.22 No.1

Endocrine disruptors have been concerned in toxicology but now challenged as physiological point especially concerned with exposing dose and period. In this study the low-dose chronic administration of di(2-ethylhexyl) phthaltae (DEHP) during reproductive period was examined to evaluate the possible roles. Adult male and female CD-1 mice were exposed to DEHP with drinking water containing 133 g/L and 1,330 ㎍/L DEHP in water according to OECD 433 guide line and sacrificed just after weaning. The weights of uterus and ovary were decreased by drinking of 1,330 ㎍/L DEHP water. There was not adverse effects on either accumulated mating rate and mating rate depend on estrus stage, pregnancy duration, and sex ration at birth. However, the accumulated rate of successful delivery and litter size were significantly high at 1,330 ㎍/L DEHP water. The number of epididymal sperm was significantly increased by drinking of 1,330 ㎍/L DEHP water. In addition, the number of follicles (primary, secondary, tertiary) were more many than control at 1,330 ㎍/L DEHP water drunk mother. Though further studies are needed to identify what are the mechanism of DEHP in folliculogenesis and spermatogenesis. From this study we firstly report the effect of low-dose chronic administration of DEHP with drinking could change the ovarian follicle population size and spermatogenesis rate. Put together, those finding is different from previous high-dose effects and suggest the physiological role of DEHP in gonads and uterus.

A Novel Self-Aligned 4-Bit SONOS-Type Nonvolatile Memory Cell With T-Gate and I-Shaped FinFET Structure

Sunyeong Lee,Yong Woo Jeon,Tsu-Jae King Liu,Dae Hwan Kim,Dong Myong Kim IEEE 2010 IEEE transactions on electron devices Vol.57 No.8

<P>We propose a novel 4-bit self-aligned SONOS-type nonvolatile memory (NVM) cell with a T-gate and I-shaped FinFET structure for practical implementation with high storage density and better reliability. In order to obtain enhanced reliability characteristics, a modified Fowler-Nordheim tunneling mechanism is employed for programming along the channel length direction, while a band-to-band hot hole injection is used for erasing along the channel width direction. With separated paths for program and erase, improved device performance is obtained with sensing margin. In order to improve the immunity to second-bit effects, the gate-induced drain leakage current method, which is a charge detection method and highly sensitive to the locally stored charges, is employed for the reading of the stored data. In terms of the scalability, we confirmed by 2-D technology computer-aided design simulation that the proposed NVM cell with channel length <I>L</I> = 50 nm operates with enough sensing margin and high-density ( ~ 5 F<SUP>2</SUP>/bit) NVM by the crossed cell array architecture.</P>

A Novel Capacitorless DRAM Cell Using Superlattice Bandgap-Engineered (SBE) Structure With 30-nm Channel Length

Sunyeong Lee,Ja Sun Shin,Jaeman Jang,Hagyoul Bae,Daeyoun Yun,Jieun Lee,Dae Hwan Kim,Dong Myong Kim IEEE 2011 IEEE TRANSACTIONS ON NANOTECHNOLOGY Vol.10 No.5

<P>We propose a novel SiGe superlattice bandgap-engineered (SBE) capacitorless dynamic random access memory (DRAM) cell with 30-nm channel length as a next-generation DRAM cell with high storage density and long retention time for practical implementation by 2-D technology computer-aided design simulation. The SBE capacitorless DRAM cell uses a common source structure and different metal layers for the top gate word line (WL) from the bottom gate WL to realize a 6F<SUP>2</SUP> feature size. Thanks to the Si<SUB>0.8</SUB>Ge<SUB>0.2</SUB> superlattice quantum well and silicon dioxide (SiO<SUB>2</SUB>) physical barrier, we obtained 213 μA/μm for the sensing margin and about 10 ms for the retention time.</P>

Disturbing Effects of Chronic Low-dose 4-Nonylphenol exposing on Gonadal Weight and Reproductive Outcome over One-generation

Sunyeong Cha,Jeong Won Baek,Hye Jin Ji,Jun Hee Choi,Chaelim Kim,Min Young Lee,Yeon Jeong Hwang,Eunhyeok Yang,Sung-Ho Lee,Hyo-il Jung,Yong-Pil Cheon 한국발생생물학회 2017 발생과 생식 Vol.21 No.2

4-Nonylphenol (NP) is a surfactant that is a well-known and widespread estrogenic endocrine disrupting chemical (EDC). Although it has been known that the affinity of NP to ERs is low, it has been suggested that low-dose NP has toxicity. In the present study, the endocrine disrupting effects on reproduction, and the weight of gonads, epididymis, and uterus were evaluated with the chronic lower-dose NP exposing. This study was designed by following the OECD test guideline 443 and subjected to a complete necropsy. In male, NP had an effect on the weight of the testis and epididymis in both F0 and F1. In females, NP decreased the weight of ovary and uterus in F0 but not in pre-pubertal F1 pubs. Fertility of male and female in F0 or F1 was no related with NP administration. The number of caudal-epididymal sperm by body weight (BW) was not different between groups in both F0 and F1. Besides, the difference of the sperm number between generations was not detected. The number of ovulated oocytes was similar between groups in F0, but significantly decreased in NP 50 group of F1. The litter size and sex ratios of offspring in F1 and F2 were not different. The accumulated mating rate and gestation period were not affected by the NP administration. Those results shows that chronic lower-dose NP administration has an effect of endocrine disruptor on the weight of gonads and epididymis of F0 and F1 but not in reproduction. Based on the results, it is suggested that chronic lower-dose NP exposing causes endocrine disruption in the weight of gonad and epididymis but not in the reproductive ability of next generations.

Nonmonotonic Effects of Chronic Low-Dose Di(2-ethylhexyl) Phthalate on Gonadal Weight and Reproduction

Cha, Sunyeong,Jung, Kayeon,Lee, Min Young,Hwang, Yeon Jeong,Yang, Eunhyeok,Lee, Sung-Ho,Jung, Hyo-il,Cheon, Yong-Pil The Korean Society of Developmental Biology 2018 발생과 생식 Vol.22 No.1

Endocrine disruptors have been concerned in toxicology but now challenged as physiological point especially concerned with exposing dose and period. In this study the low-dose chronic administration of di(2-ethylhexyl) phthaltae (DEHP) during reproductive period was examined to evaluate the possible roles. Adult male and female CD-1 mice were exposed to DEHP with drinking water containing $133{\mu}g/L$ and $1,330{\mu}g/L$ DEHP in water according to OECD 433 guide line and sacrificed just after weaning. The weights of uterus and ovary were decreased by drinking of $1,330{\mu}g/L$ DEHP water. There was not adverse effects on either accumulated mating rate and mating rate depend on estrus stage, pregnancy duration, and sex ration at birth. However, the accumulated rate of successful delivery and litter size were significantly high at $1,330{\mu}g/L$ DEHP water. The number of epididymal sperm was significantly increased by drinking of $1,330{\mu}g/L$ DEHP water. In addition, the number of follicles (primary, secondary, tertiary) were more many than control at $1,330{\mu}g/L$ DEHP water drunk mother. Though further studies are needed to identify what are the mechanism of DEHP in folliculogenesis and spermatogenesis. From this study we firstly report the effect of low-dose chronic administration of DEHP with drinking could change the ovarian follicle population size and spermatogenesis rate. Put together, those finding is different from previous high-dose effects and suggest the physiological role of DEHP in gonads and uterus.

Disturbing Effects of Chronic Low-dose 4-Nonylphenol exposing on Gonadal Weight and Reproductive Outcome over One-generation

Cha, Sunyeong,Baek, Jeong Won,Ji, Hye Jin,Choi, Jun Hee,Kim, Chaelim,Lee, Min Young,Hwang, Yeon Jeong,Yang, Eunhyeok,Lee, Sung-Ho,Jung, Hyo-il,Cheon, Yong-Pil The Korean Society of Developmental Biology 2017 발생과 생식 Vol.21 No.2

4-Nonylphenol (NP) is a surfactant that is a well-known and widespread estrogenic endocrine disrupting chemical (EDC). Although it has been known that the affinity of NP to ERs is low, it has been suggested that low-dose NP has toxicity. In the present study, the endocrine disrupting effects on reproduction, and the weight of gonads, epididymis, and uterus were evaluated with the chronic lower-dose NP exposing. This study was designed by following the OECD test guideline 443 and subjected to a complete necropsy. In male, NP had an effect on the weight of the testis and epididymis in both $F_0$ and $F_1$. In females, NP decreased the weight of ovary and uterus in $F_0$ but not in pre-pubertal $F_1$ pubs. Fertility of male and female in $F_0$ or $F_1$ was no related with NP administration. The number of caudal-epididymal sperm by body weight (BW) was not different between groups in both $F_0$ and $F_1$. Besides, the difference of the sperm number between generations was not detected. The number of ovulated oocytes was similar between groups in $F_0$, but significantly decreased in NP 50 group of $F_1$. The litter size and sex ratios of offspring in $F_1$ and $F_2$ were not different. The accumulated mating rate and gestation period were not affected by the NP administration. Those results shows that chronic lower-dose NP administration has an effect of endocrine disruptor on the weight of gonads and epididymis of $F_0$ and $F_1$ but not in reproduction. Based on the results, it is suggested that chronic lower-dose NP exposing causes endocrine disruption in the weight of gonad and epididymis but not in the reproductive ability of next generations.

큐브위성의 전력시스템 설계를 위한 소프트웨어 테스트베드 설계

이성준(Seongjun Lee),임남규(Namgyu Lim),이선영(Sunyeong Lee),백진성(Jinsung Baek),박희망(Huimang Park),김준석(Junseok Kim) 전력전자학회 2018 전력전자학술대회 논문집 Vol.2018 No.7

놀이중심 보육과정에서 나타난 보육실습 지도교사의 경험 탐색

이진화 ( Jinwha Lee ),이지혜 ( Jihye Lee ),김선영 ( Sunyeong Kim ) 인문사회 21 2023 인문사회 21 Vol.14 No.1

연구 목적: 이 연구는 놀이중심 보육과정에서 보육실습지도를 경험한 보육교사의 이야기를 분석하여 질적으로 향상된 보육실습이 이루어지는데 필요한 시사점을 도출하는데 목적이 있다. 연구 방법: 놀이중심 보육과정에서 보육실습지도 경험을 가진 10명의 현직교사 대상으로 심층면담을 진행하였고, Hatch(2002)의 귀납적 분석 방법을 사용하였다. 연구 내용: 첫째, 보육실습 지도교사들은 ‘놀이중심 보육과정’에 자신도 교사로서 적응해가는 과정에서 보육실습생에게 바람직한 모델로 보여야 한다는 점과 이전 보육과정에 맞춘 보육실습 지도체제 및 양식들을 그대로 사용하는 것에서 혼란과 갈등을 겪고 있었다. 둘째, 변화된 보육과정에 근거한 새로운 보육실습 가이드라인 제시, 보육실습 지도교사를 위한 교육기회 등의 필요성이 나타났다. 결론 및 제언: 보육실습 지도교사를 위한 교사교육 제공, 새로운 보육실습지도 방안 마련과 대학과 어린이집 간 협력이 강화되어야 함을 시사한다. This study was aimed to derive implications to improve the child care practicum for pre-service teachers through analyzing the experiences of supervisors in the play-centered child care curriculum. In-depth interviews were conducted with 10 supervisors and the data were analyzed to use the method of Hatch (2002). The main results were as followed. First, in the process of adapting to the new curriculum, supervisors were facing confusion and conflict in that they had to be seen as a desirable role model for pre-service teachers and in using the child care practicum system and form based on the previous child care curriculum. Second, there was a need to create new practice guidelines based on the changed child care curriculum and providing teaching educational opportunities for supervisors. It implies that providing educational opportunities for supervisors, improving child care practice guidelines, and strengthening cooperation between universities and child care centers.