포톤 계수 방식의 $32{\times}32$ 픽셀 어레이를 갖는 디지털 CMOS X-ray 이미지 센서 설계

성관영,김태호,황윤금,전성채,진승오,허영,하판봉,박무훈,김영희,Sung, Kwan-Young,Kim, Tae-Ho,Hwang, Yoon-Geum,Jeon, Sung-Chae,Jin, Seung-Oh,Huh, Young,Ha, Pan-Bong,Park, Mu-Hun,Kim, Young-Hee 한국정보통신학회 2008 한국정보통신학회논문지 Vol.12 No.7

본 논문에서는 $0.18{\mu}m$ triple-well CMOS 공정을 사용하여 포톤계수 방식의 $32{\times}32$ 픽셀 어레이를 갖는 CMOS ray 영상센서를 설계하였다. 설계된 영상센서의 카픽셀은 $100{\times}100\;{\mu}m2$ 면적을 가지고 있고 약 400개의 트랜지스터로 구성되어 있으며, 범프 본딩을 통해 ray 검출기와 CSA(Charge Sensitive Amplifier)의 연결을 위한 $50{\times}50{\mu}m2$의 오픈패드를 가지고 있다. 각각의 싱글픽셀 CSA에서 전압 바이어스 회로를 사용한 folded cascode CMOS OP amp 대신 레이아웃 면적을 줄이기 위하여 self biased folded cascode CMOS OP amp를 이용하였으며, 계수 모드 진입 전후에 CLK에서 발생 할 수 있는 short pulse를 제거하는 15bit LFSR 계수기 (Linear Feedback Shift Register Counter) 클럭 발생회로를 제안하였으며, 읽기 모드에서 CMOS X-ray 영상센서의 최대 전류를 줄이기 위하여 열 어드레스 디코더를 이용하여 한 열씩 읽도록 설계하였다. In this paper, x-ray image sensor of photon counting type having a $32{\times}32$ pixel array is designed with $0.18{\mu}m$ triple-well CMOS process. Each pixel of the designed image sensor has an area of loot $100{\times}100\;{\mu}m2$ and is composed of about 400 transistors. It has an open pad of an area of $50{\times}50{\mu}m2$ of CSA(charge Sensitive Amplifier) with x-ray detector through a bump bonding. To reduce layout size, self-biased folded cascode CMOS OP amp is used instead of folded cascode OP amp with voltage bias circuit at each single-pixel CSA, and 15-bit LFSR(Linear Feedback Shift Register) counter clock generator is proposed to remove short pulse which occurs from the clock before and after it enters the counting mode. And it is designed that sensor data can be read out of the sensor column by column using a column address decoder to reduce the maximum current of the CMOS x-ray image sensor in the readout mode.

Characterization of Inkjet-Printed Silver Patterns for Application to Printed Circuit Board (PCB)

Shin, Kwon-Yong,Lee, Minsu,Kang, Heuiseok,Kang, Kyungtae,Hwang, Jun Young,Kim, Jung-Mu,Lee, Sang-Ho The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.3

In this paper, we describe the analysis of inkjet-printed silver (Ag) patterns on epoxy-coated substrates according to several reliability evaluation test method guidelines for conventional printed circuit boards (PCB). To prepare patterns for the reliability analysis, various regular test patterns were created by Ag inkjet printing on flame retardant 4 (FR4) and polyimide (PI) substrates coated with epoxy for each test method. We coated the substrates with an epoxy primer layer to control the surface energy during printing of the patterns. The contact angle of the ink to the coated epoxy primer was $69^{\circ}$, and its surface energy was 18.6 $mJ/m^2$. Also, the substrate temperature was set at $70^{\circ}C$. We were able to obtain continuous line patterns by inkjet printing with a droplet spacing of $60{\mu}m$. The reliability evaluation tests included the dielectric withstanding voltage, adhesive strength, thermal shock, pressure cooker, bending, uniformity of line-width and spacing, and high-frequency transmission loss tests.

Two-Dimensional Optical Interconnection Based on Two-Layered Optical Printed Circuit Board

Hwang, Sung Hwan,Cho, Mu Hee,Kang, Sae-Kyoung,Lee, Tae-Woo,Park, Hyo-Hoon,Rho, Byung Sup IEEE 2007 IEEE photonics technology letters Vol.19 No.5-8

<P>The demonstration of an optical platform based on an optical printed circuit board (OPCB) was shown for two-dimensional (2-D) chip-to-chip optical interconnection. The optical platform was designed for 96 Gb/s total throughput which was 2 layers times 4 channels times 4 parallel links times 3 Gb/s/ch and using a passive assembly technology. We fabricated three main components for the 2-D optical interconnection; two-layered six-channel fiber- and connector-embedded OPCB, two-layered six-channel 90deg-bent fiber connectors, and 2-D optical transmitter/receiver (Tx/Rx) modules. The total optical loss from the Tx to the Rx was measured to approximately be -5.3 dB. The optical interconnection using an optical platform was successfully achieved with 3-Gb/s/ch data transmission</P>

A comparison of meta-analysis results with and without adjustment for the healthy worker effect: cancer mortality among workers in the semiconductor industry

Sung-Ho Hwang,Moon-Young Park,Won Jin Lee,Inho Park,Kimyong Hong,Donguk Park,Kyoung-Mu Lee 한국역학회 2021 Epidemiology and Health Vol.43 No.-

OBJECTIVES: This study compared the results of meta-analysis with and without adjustment for the healthy worker effect on the association between working in the semiconductor industry and cancer mortality. METHODS: Six studies that reported standardized mortality ratios (SMRs) for cancers were selected for meta-analysis. Using a random-effects model, the SMR results from each study were combined for all cancers and leukemias to estimate the summary SMRs (95% confidence interval, CI). To adjust for the healthy worker effect, the relative standardized mortality ratio (rSMR=SMRx/SMRnot x) were calculated using observed and expected counts for the specific cause of interest (i.e., all cancers and leukemias) and the observed and expected counts for all other causes of mortality. Then, the rSMR results were combined to estimate the summary rSMRs (95% CIs). RESULTS: The SMRs for all causes of mortality among semiconductor industry workers ranged from 0.25 to 0.80, which reflects a significant healthy worker effect. A remarkable difference was found between the summary SMRs and the summary rSMRs. The summary SMR for all cancers was 0.70 (95% CI, 0.63 to 0.79) whereas the summary rSMR was 1.38 (95% CI, 1.20 to 1.59). The summary SMR for leukemia was 0.88 (95% CI, 0.72 to 1.07), and the summary rSMR was 1.88 (95% CI, 1.20 to 2.95). CONCLUSIONS: Our results suggest that adjustment for the healthy worker effect (i.e., rSMR) may be useful in meta-analyses of cohort studies reporting SMRs.

High-Efficiency, Solid-State, Dye-Sensitized Solar Cells Using Hierarchically Structured TiO₂ Nanofibers

Hwang, Daesub,Jo, Seong Mu,Kim, Dong Young,Armel, Vanessa,MacFarlane, Douglas R.,Jang, Sung-Yeon American Chemical Society 2011 ACS APPLIED MATERIALS & INTERFACES Vol.3 No.5

<P>High-performance, room-temperature (RT), solid-state dye-sensitized solar cells (DSSCs) were fabricated using hierarchically structured TiO<SUB>2</SUB> nanofiber (HS-NF) electrodes and plastic crystal (PC)-based solid-state electrolytes. The electrospun HS-NF photoelectrodes possessed a unique morphology in which submicrometer-scale core fibers are interconnected and the nanorods are dendrited onto the fibers. This nanorod-in-nanofiber morphology yielded porosity at both the mesopore and macropore level. The macropores, steming from the interfiber space, afforded high pore volumes to facilitate the infiltration of the PC electrolytes, whereas the mesoporous nanorod dendrites offered high surface area for enhanced dye loading. The solid-state DSSCs using HS-NFs (DSSC-NF) demonstrated improved power conversion efficiency (PCE) compared to conventional TiO<SUB>2</SUB> nanoparticle (NP) based DSSCs (DSSC-NP). The improved performance (>2-fold) of the DSSC-NFs was due to the reduced internal series resistance (<I>R</I><SUB>s</SUB>) and the enhanced charge recombination lifetime (τ<SUB>r</SUB>) determined by electrochemical impedance spectroscopy and intensity modulated photocurrent/photovoltage spectroscopy. The easy penetration of the PC electrolytes into HS-NF layers via the macropores reduces <I>R</I><SUB>s</SUB> significantly, improving the fill factor (FF) of the resulting DSSC-NFs. The τ<SUB>r</SUB> difference between the DSSC-NF and DSSC-NP in the PC electrolytes was extraordinary (∼ 14 times) compared to reported results in conventional organic liquid electrolytes. The optimized PCE of DSSC-NF using the PC electrolytes was 6.54, 7.69, and 7.93% at the light intensity of 100, 50, and 30 mW cm<SUP>−2</SUP>, respectively, with increased charge collection efficiency (>40%). This is the best performing RT solid-state DSSC using a PC electrolyte. Considering the fact that most reported quasi-solid state or nonvolatile electrolytes require higher iodine contents for efficient ion transport, our HS-NFs are a promising morphology for such electrolytes that have limited ion mass transport.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2011/aamick.2011.3.issue-5/am200092j/production/images/medium/am-2011-00092j_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am200092j'>ACS Electronic Supporting Info</A></P>

Thirteen-Week Repeated-Dose Oral Toxicity of Licorice Root in F344 Rats

Sang-Bum Koh,Jae-Hwang Jeong,Mu-Yeb Seo,Jun-Yeon Lee,Dong-Seok Seo,Hak-Soo Bark,Myung-Hwa Kang,Dae-Yong Kim,Ha-Jung Sung 한국실험동물학회 2006 Laboratory Animal Research Vol.22 No.1

The purpose of this study is to investigate a potential toxicity of licorice root (LR) in Fisher 344 rats through the 13-week repeated oral treatment. Healthy Fisher 344 rats were divided into five treatment groups (2,000, 571, 163, 47, and 13 ㎎/㎏) and one control group (vehicle) of 12 males and 12 females respectively. LR was orally administered by gavage to F344 rats once a day, 5 days per week for 13 weeks. During the test period, clinical signs, mortality, body weights, necropsy findings, hematology, serum biochemistry, organ weight, histopathology, sperm count and sperm motility were evaluated. The relative liver weights were increased significantly in males of the 2,000 and 571 ㎎/㎏ groups. However, there was no histological evidence in the liver. The increased incidence of chronic nephropathy only appeared in the 2,000 ㎎/㎏ group of both male and female rats. There were no treatment-related effects on clinical signs, mortality, body weights, necropsy findings, hematology, serum biochemistry and sperm count and motility in any treatment groups. Based on these results, no-observed adverse effect level (NOAEL) of LR was 571 ㎎/㎏ in F344 rats under the conditions of the present study.

사립유치원 표준교육비 산출 연구

문무경 ( Mu Yeong Moon ),천세영 ( Se Young Chun ),황현주 ( Hyun Joo Hwang ),이성은 ( Sung Eun Lee ),이진경 ( Jin Kyung Lee ) 한국유아교육학회 2013 유아교육연구 Vol.33 No.4

본 연구는 사립유치원을 기준으로 표준유아교육비를 산출하기 위하여 전국 700여개 사립유치원 표본을 대상으로 세입세출결산서를 분석하여 표준교육비 결정모형을 도출하였다. 본 연구에서는 인건비, 학교운영비, 교육활동경비, 수익자부담경비, 시설비를 표준유아교육비 구성 항목으로 설정하였다. 원아 1인당 연간 총교육비는 중규모(총 원아 50명이상 150명 미만) 유치원 만5세아를 기준으로 2,314,103원(인건비 제외), 교원1인당 인건비는 25,199,661원, 직원1인당 표준인건비는 7,078,641원으로 산출되었다. 본 연구에서 산출된 사립유치원의 원아 1인당 연간 표준유아교육비는 인건비를 포함하거나 제외한 경우 모두 사립유치원(4,598천원)이 공립유치원(5,235천원)보다 낮은 수준으로 나타났다. This study reviews the current criteria for and items composing standard unit costs of early childhood education and examines the financial characteristics of private kindergartens toward setting more realistic and reasonable standard unit costs for kindergarten education. The composition items in this study are set to include costs for personnel, management(e.g., electricity, heating), educational activities, facility maintenance, and beneficiary charge. Annual accounting reports of about 700 private kindergartens were collected nation-wide. Regression analysis of the data reveals that the annual standard educational unit cost for 5 year olds without personnel expenses is 2,314,103 KRW(approximately USD 2,050). Annual salaries for teachers and staff are 25,199,661 KRW and 7,078,641 KRW respectively. The annual standard unit cost of education in private kindergartens is set less than that in public ones in both cases of including and excluding personnel expenses.

헬리콥터 무베이링 메인 로터 허브 시스템의 구조 건전성에 관한 연구

이무형 ( Mu Hyoung Lee ),박일경 ( Ill Kyoung Park ),김성준 ( Sung Joon Kim ),황인희 ( In Hee Hwang ),김태주 ( Tae Joo Kim ) 한국항공운항학회 2012 한국항공운항학회지 Vol.20 No.4

Rotor system is a very important part which produce lift, thrust and control force in helicopter. Component of rotor system must have structural integrity for applied load. The estimation of structural integrity is regarded greatly as important in aerospace field. In this study, the process of structural analysis performed for bearingless main rotor system of helicopter. The composite flexbeam and torque tube of bearingless main rotor are very thick, so 3D layered soild elements of MSC.PATRAN were used to get the finite element analysis results. To estimate structural integrity, non-linear static analysis considering geometric non-linearity is performed. In addition, detailed finete element analysis and non-linear static analysis are performed to consider the stress concentration for fitting effect and contact surface. The estimation process of structural integrity for bearingless main rotor system of helicopter may help the design.

배양된 멜라닌세포에서 UVB 일회 조사후 형태 및 증식의 변화

이승한(Sung Han Lee),황정열(Jung Yuel Hwang),이무형(Mu Hyoung Lee),박재경(Jai Kyung Park),허충림(Choong Rim Haw) 대한피부과학회 1992 대한피부과학회지 Vol.30 No.6

In humans, the major stimulus for cutaneous pigmentation is ultraviolet radiation. Little is known about the mechanism underlying this response, in part, because of the complexity of the interactions involving the whole epidermis. The present stucy was undertake to evaluate the effects of a single exposure of UVB on cultured normal melanocytes. Melanocytes were exposed to UVB from 5.1 mJ/cm to 203 mJ/cm. The results were as follows : 1. The main morphologic changes in UVB-exposed groups w re larger sized cells, more blunted dendrites, and shorter dendrites than in the control group. These cells increased sized according to the increased doses of VVB, but above 101.5 mJ/cm, the melanocytes shrunk and were destroyed. 2. From 20.3 mJ/cm of UVB, the proliferation of melanocyte was decreased, Especially, there was statistical!y significant difference above 50.8 mJ/cm (p<0.05, p<0.01). 3. The antiproliferativo effect increased with the passage of tirie after UVB exposure. So, cell count could not be done in 101.5 mJ/cm and 203 mJ/cm on the third day, and in 50.8 mJ/cm, 101.5 m J/cm and 203 mJ/cm on the seventh day. 4. Statistically the melanin content per well was significantl dicreased to 11-28% of each control group with dose above 50.8 mJ/cm (p<0.05, p<0.01). The melanin content per cell was increased to 107-128% of each control group when doses were below 20.3 mJ/cm and decreased to 49-79% of each control group when above 0.8 mJ/cm on the third day, but there was no statistically significant difference. In summary, when melarocytes were exposed to UVB, morphclogic changes progressed to cell differentiation. The results also suggested that a low or dose of UVB has an antiproliferative arid mild melanogenic effect, and a higher dose of UVB has a direct cytotoxic effect. (Kor J Dermatal 1992;30(6):802-810)

길경 Saponin이 고지방식이를 한 흰쥐의 혈청, 간장 및 분변 지질 함량에 미치는 영향

박무희(Mu-Hee Park),이영주(Young-Ju Lee),황성원(Sung-Wong Hwang),한준표(Jun-Pyo Han),배만종(Man-Jong Bae) 한국식품영양과학회 1994 한국식품영양과학회지 Vol.23 No.4

6주간 고지방식이를 섭취한 흰쥐에 있어서 길경 saponin이 지방 축적 억제와 대사에 미치는 영향을 검토하고자 혈청과 간장 및 분변 중 지방 성분을 생화학적으로 분석하여 다음과 같은 결과를 얻었다. 1. 혈청 및 간장중의 총지질, 총콜레스테롤 및 중성지방 함량은 길경 saponin군이 대조군에 비하여 유의한 감소를 보였다. 2. 분변 중 총지질 및 총콜레스테롤 함량은 대조군과 비교할 때 길경 saponin군이 다소 배설이 증가되었으나, 유의성은 인정되지 않았다. This study was conducted to investigate the effect of Platycodi radix saponin (PRS) on the reduction of lipid status in rats fed on high fat diet for 6 weeks after which lipid contents were measured in serum, liver and feces. The results obtained from this study are as follows; That the levels of total lipid, total cholesterol and triglyceride in serum and liver were significantly lower in the PRS group as compared with the control group. The contents of total lipid and total cholesterol excreted in the feces were tended to be slightly increase in PRS group compared to the control group, which were not significant.