UHF RFID 태그 칩용 저전력 EEPROM설계

이원재,이재형,박경환,이정환,임규호,강형근,고봉진,박무훈,하판봉,김영희,Yi, Won-Jae,Lee, Jae-Hyung,Park, Kyung-Hwan,Lee, Jung-Hwan,Lim, Gyu-Ho,Kang, Hyung-Geun,Ko, Bong-Jin,Park, Mu-Hun,Ha, Pan-Bong,Kim, Young-Hee 한국정보통신학회 2006 한국정보통신학회논문지 Vol.10 No.3

본 논문에서 는 플래쉬 셀을 사용하여 수동형 UHF RFID 태그 칩에 사용되는 저전력 1Kb 동기식 EEPROM을 설계하였다. 저전력 EEPROM을 구현하기 위한 방법으로 다음과 같은 4가지 방법을 제안하였다. 첫째, VDD(=1.5V)와 VDDP(=2.5V)의 이중 전원 공급전압 방식을 사용하였고, 둘째, 동기식 회로 설계에서 클럭(clock) 신호가 계속 클럭킹(clocking)으로 인한 스위칭 전류(switching current)가 흐르는 것을 막기 위해 CKE(Clock Enable) 신호를 사용하였다. 셋째, 읽기 사이클에서 전류 센싱(current sensing) 방식 대신 저전력 소모를 갖는 clocked inverter를 사용한 센싱 방식을 사용하였으며, 넷째, 쓰기 모드시 Voltage-up 변환기(converter) 회로를 사용하여 기준전압 발생기(Reference Voltage Generator)에는 저전압인 VDD를 사용할 수 있도록 하여 전력 소모를 줄일 수가 있었다. $0.25{\mu}m$ EEPROM 공정을 이용하여 칩을 제작하였으며, 1Kb EEPROM을 설계한 결과 읽기 모드와 쓰기 모드 시에 소모되는 전력은 각각 $4.25{\mu}W$와 $25{\mu}W$이고, 레이아웃 면적(layout area)은 $646.3\times657.68{\mu}m^2$이다. In this paper, a low-power 1Kb synchronous EEPROM is designed with flash cells for passive UHF RFID tag chips. To make a low-power EEPROM, four techniques are newly proposed. Firstly, dual power supply voltages VDD(1.5V) and VDDP(2.5V), are used. Secondly, CKE signal is used to remove switching current due to clocking of synchronous circuits. Thirdly, a low-speed but low-power sensing scheme using clocked inverters is used instead of the conventional current sensing method. Lastly, the low-voltage, VDD for the reference voltage generator is supplied by using the Voltage-up converter in write cycle. An EEPROM is fabricated with the $0.25{\mu}m$ EEPROM process. Simulation results show that power dissipations are $4.25{\mu}W$ in the read cycle and $25{\mu}W$ in the write cycle, respectively. The layout area is $646.3\times657.68{\mu}m^2$.

A comparative study on the inhibitory effects of mast cell-mediated allergic reactions by artificially cultured and wild Acanthopanax senticosus

Yi, Jin-Mu,Jeong, Hyun-Ja,Shim, Kyung-Shik,Lee, Kang-Yong,Kim, Jeong-Sook,Zheng, Cui,Tomoko, Jippo,Lee, Young-Mi Kyung Hee Oriental Medicine Research Center 2000 International journal of oriental medicine Vol.1 No.2

We compared the effect between CAS and WAS(root, stem) on mast cell-mediated allergic reaction. CAS, WAS-root and WAS-stem, significantly inhibited compound 48/80-induced systemic allergic reaction(1g/kg) and histamine release from RPMC(1mg/ml). CAS, WAS-root and WAS-stem also inhibited passive cutaneous anaphylactic reaction. In addition, IgE-induced $TNF-{\alpha}$ secretion from RBL-2H3 was inhibited by pretreatment of CAS, WAS-root or WAS-stem$(0.01{\mu}g/ml)$. Taken together, inhibitory effect on mast cell-mediated allergic reactions of WAS-root is greater than those of WAS-stem but less than those of CAS.

Risk Assessment of 5-Chloro-2-Methylisothiazol-3(2H)-One/2-Methylisothiazol-3(2H)-One (CMIT/MIT) Used as a Preservative in Cosmetics

Kim, Min Kook,Kim, Kyu-Bong,Lee, Joo Young,Kwack, Seung Jun,Kwon, Yong Chan,Kang, Ji Soo,Kim, Hyung Sik,Lee, Byung-Mu Korean Society of ToxicologyKorea Environmental Mu 2019 Toxicological Research Vol.35 No.2

The mixture of 5-chloro-2-methylisothiazol-3(2H)-one (CMIT) and 2-methylisothiazol-3(2H)-one (MIT), CMIT/MIT, is a preservative in cosmetics. CMIT/MIT is a highly effective preservative; however, it is also a commonly known skin sensitizer. Therefore, in the present study, a risk assessment for safety management of CMIT/MIT was conducted on products containing 0.0015% of CMIT/MIT, which is the maximum MIT level allowed in current products. The no observed adverse effect level (NOAEL) for CMIT/MIT was 2.8 mg/kg bw/day obtained from a two-generation reproductive toxicity test, and the skin sensitization toxicity standard value for CMIT/MIT, or the no expected sensitization induction level (NESIL), was $1.25{\mu}g/cm^2/day$ in humans. According to a calculation of body exposure to cosmetics use, the systemic exposure dosage (SED) was calculated as 0.00423 mg/kg bw/day when leave-on and rinse-off products were considered. Additionally, the consumer exposure level (CEL) amounted to $0.77512{\mu}g/cm^2/day$ for all representative cosmetics and $0.00584{\mu}g/cm^2/day$ for rinse-off products only. As a result, the non-cancer margin of safety (MOS) was calculated as 633, and CMIT/MIT was determined to be safe when all representative cosmetics were evaluated. In addition, the skin sensitization acceptable exposure level (AEL)/CEL was calculated as 0.00538 for all representative cosmetics and 2.14225 for rinse-off products; thus, CMIT/MIT was considered a skin sensitizer when all representative cosmetics were evaluated. Current regulations indicate that CMIT/MIT can only be used at concentrations 0.0015% or less and is prohibited from use in other cosmetics products. According to the results of this risk assessment, the CMIT/MIT regulatory values currently used in cosmetics are evaluated as appropriate.

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.

X-ray 이미지 센서용 싱글 픽셀 포톤 카운터 설계

백승면,김태호,강형근,전성채,진승오,허영,하판봉,박무훈,김영희,Baek, Seung-Myun,Kim, Tae-Ho,Kang, Hyung-Geun,Jeon, Sung-Chae,Jin, Seung-Oh,Huh, Young,Ha, Pan-Bong,Park, Mu-Hun,Kim, Young-Hee 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.2

본 논문에서는 디지털 의료 영상 및 진단 분야 그리고 산업용으로도 활용 가능한 싱글 포톤 계수형 영상센서를 $0.18{\mu}m$ triple-well CMOS(Complementary Metal Oxide Semiconductor) 공정을 사용하여 설계하였다. 설계된 Readout 칩용 싱글 픽셀은 디지털 X-ray 이미지 센서모듈을 간단화 하기 위해 단일 전원전압을 사용하였으며, Preamplifier의 출력 전압인 signal voltage(${\Delta}Vs$)를 크게 하기 위해 Folded Cascode CMOS OP amp를 이용한 Preamplifier를 설계하였으며, 기존의 Readout 칩 외부에서 인가하던 threshold voltage를 Readout 칩 내부에서 생성해 줄 수 있도록 Externally Tunable Threshold Voltage Generator 회로를 새롭게 제안하였다. 그리고, Photo Diode에서 발생하는 Dark Current Noise를 제거하기 위한 Dark Current Compensation 회로를 제안하였으며, 고속 counting이 가능하고, layout 면적이 작은 15bit LFSR(Linear Feedback Shift Resister) Counter를 설계하였다. A single pixel photon counting type image sensor which is applicable for medical diagnosis with digitally obtained image and industrial purpose has been designed with $0.18{\mu}m$ triple-well CMOS process. The designed single pixel for readout chip is able to be operated by single supply voltage to simplify digital X-ray image sensor module and a preamplifier which is consist of folded cascode CMOS operational amplifier has been designed to enlarge signal voltage(${\Delta}Vs$), the output voltage of preamplifier. And an externally tunable threshold voltage generator circuit which generates threshold voltage in the readout chip has been newly proposed against the conventional external threshold voltage supply. In addition, A dark current compensation circuit for reducing dark current noise from photo diode is proposed and 15bit LFSR(Linear Feedback Shift Resister) Counter which is able to have high counting frequency and small layout area is designed.

TFT -LCD 구동 IC용 커패시터 내장형 DC-DC 변환기 설계

임규호,강형근,이재형,손기성,조기석,백승면,성관영,이용진,박무훈,하판봉,김영희,Lim Gyu-Ho,Kang Hyung-Geun,Lee Jae-Hyung,Sohn Ki-Sung,Cho Ki-Seok,Baek Seung-Myun,Sung Kwan-Young,Li Long-Zhen,Park Mu-Hun,Ha Pan-Bong,Kim Young-Hee 한국정보통신학회 2006 한국정보통신학회논문지 Vol.10 No.7

A non-overlap boosted-clock charge pump(NBCCP) with internal pumping capacitor, an advantageous circuit from a minimizing point of TFT-LCD driver IC module, is proposed in this paper. By using the non-overlap boosted-clock swinging in 2VDC voltage, the number of pumping stages is reduced to half and a back current of pumping charge from charge pumping node to input stage is also prevented compared with conventional cross-coupled charge pump with internal pumping capacitor. As a result, pumping current of the proposed NBCCP circuit is increased more than conventional cross-coupled charge pump, and a layout area is decreased. A proposed DC-DC converter for TFT-LCD driver IC is designed with $0.18{\mu}m$ triple-well CMOS process and a test chip is in the marking. 본 논문에서는 TFT-LCD 구동 IC 모듈의 소형화측면에서 유리한 DC-DC 변환기 회로인 펌핑 커패시터 내장형 비중첩 부스트-클락 전하펌프 (Non-overlap Boosted-Clock Charge Pump: NBCCP) 회로가 제안되었다 .2VDC 전압으로 스윙하는 비중첩 부스트-클럭의 사용으로 기존의 펌핑 커패시터 내장형 크로스-커플드 전하펌프에 비해 펌핑 단의 수를 반으로 줄일 수 있었고, 전하 펌핑 노드의 펌핑된 전하가 입력 단으로 역류되는 현상을 방지하였다 . 그 결과 제안된 펌핑 커패시터 내장형 비중첩 부스트-클럭 전하펌프 회로는 기존의 펌핑 커패시터 내장형 크로스-커플드 전하펌프에 비해 펌핑 전류가 증가하였고, 레이아웃 면적은 감소되었다. 제안된 TFT-LCD 구동 IC용 DC-DC 변환기 회로를 $0.18{\mu}m$ Triple-Well CMOS 공정을 사용하여 설계하고, 테스트 칩을 제작 중에 있다.

급냉 제강슬래그를 잔골재로 사용한 차폐콘크리트의 공학적 특성에 관한 실험적 연구

강기웅,조성현,정원섭,권기주,김진만,김무한 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

The steel slag, a by~product which is produced during the manufacture of steel by refining pig iron, is mainly used as road materials after aging it. It is necessary to age steel slag for long time in air because the reaction with water and free-CaO in steel slag could make the expansion of volume. This problem prevents steel slag from being used as aggregate for concrete. However, steel slag used in this study was controled by a air-jet method which rapidly cools substance melted at a high temperature. The rapid-chilling method prevents from generation of free-CaO in steel slag. The rapid-chilled steel slag is similar to be spherical shape and has the heavier specific gravity than natural aggregate. Therefore, it could be used to manufacture radiation shielding concrete as fine aggregate. This paper investigated the engineering properties of radiation shielding concrete when using rapid-chilled steel slag as fine aggregate. As results of this study, the increase of use of rapid-chilled steel slag decreased the desirable water content of concrete but developed the rate of radiation shielding of concrete. The strength of concrete using it is similar to that of concrete using river sand.

산소 결핍도 변화에 따른 YBa_2 Cu_3 O_7-y의 열기전력 변화

강원남,김용민,조경철,최무용 성균관대학교 기초과학연구소 1988 論文集 Vol.39 No.1

To clarify the superconducting mechanism of the high Tc oxide superconductors, we have studied the interactions among electrons and elementary excitations and the electronic energy band structure by measuring the thermoelectric power of YBa_2 Cu_3O_7-y with various oxygen deficiencies. We have found that the major charge carriers in YBa_2Cu_3O_7-y are holes, that the width of the electronic energy band is larger than the intial estimation, and that the interaction between electrons and phnonos in the material is not strong enough to explain the high Tc super conductivity, while we have seen an evidence that there exist strong interactions between electrons and magnetic excitations.

RBC工程에 依한 LAS와 都市 混合廢水의 處理

李武康,金薰洙 慶星大學校 1988 論文集 Vol.9 No.2

In this study, though the biodegradation rate of the surfactant itself is important, of which influence to the sewage treatments is important too, and therefore, when the municipal sewage including surfactant(LAS) is treated by the activaed sludge process, large quantity of bubble is produced by aeration in the reaction tank ,and also the sludge bulking phenomenon is caused in the sedimentation tank, so the municipal sewage is applied and treated by RBC which has no such faults and its results have been obtained as follow: 1) when the LAS concentration is 0,10,50,100,200 �/�, the COD removal efficiency is 90,87,85,81 and 75%, so it is recognized that as the cocentration increase, COD removal efficiency decrease. 2) when the hydraulic retention time is 0.1 day, more than about 80% can be removed when LAS is not added, while the more the added concentration of LAS increase, the slower the biodegradation rate becomes, so it is understood that more than 0.4day is required in order to obtain the same removal efficiency as the condition of the without added LAS. 3) when LAS concentration is 0,50 and 100�/�, the sludge yield parameter, Y, is 1.086, 0.949 and 0.792�VSS/�COD respectively, and endogenous respiration parameter, kd, is 0.078, 0.088 and 0.163day?. The reaction rate constant, k, is 0.087, 0.415 and 0.415 and 0.155day? and the half velocity constant, Ks, is obtained 1187,710.1, and 360.7�COD/�respectively.

回轉圓板法을 利用한 合成洗劑廢水 處理時 動力學的 解析

이무강,김영철 慶星大學校 1992 論文集 Vol.13 No.2

A rotating biological contactor is the reactor in which influent organic substrate are aerobically oxidized by suspended biomass and attached biomass of biofilm grown on the surface of disc. The objective of this study is to investigated the factors affecting treatment efficiency of the rotating biological contactor and the kinetic parameters were obtained by Pano and Middlebrooks model. Experimental Parameters were influent LAS(Liner alkyl benzene sulfonate) and hydraulic and organic loading rate. The reactor were made of acryle semicircular tank. Disc were fabricated from bakelite resin and were 24cm in diameter and in 2mm thick. The contactor was rotated by a electric moter at 9rpm, while appoximately 40% of the surface area is submerged in the wastewater. The tank volume as values of G is measured as wastewater volume held within a tank containg a shaft of media per unit of growth convered surface on the shaft, of liter per squre meter(l/㎡). G values of 1-2 stage held 5.0 and 3-4 stage held 3.0. The immersed portion of the media is rotated in the opposite diraction as the wastewater flow to minimize any possible short-circutting along the bottom of the tank. Based on the results of the experiments, the follows conclusions are drawn. 1. The efficiency of treatment showed a tendency to largely decrease as LAS limiting concentration of treatment was 300mg/l, the LAS limiting concentration of treatment by RBC in comparsion with activated sludge are largely presented eight times or more. 2. When the synthetic detergent manufacturing wastewater was LAS concentration ranging from l00mg/l to 200mg/l, hydraulic loading rate and organic loading rate should be operated less than 60ℓ/㎡-day, 40g COD/㎡-day, respectively LAS conc. ranging from 300mg/l to 400mg/l should be operated less than 20ℓ/㎡- day, 20g CDD/㎡- day, respectively. 3. From the experimental results, the kinetic equations of completely mixed activated sludge process with sludge recycle could be applied to RBC process.