Ultra-energy-efficient analog-to-digital converters based on single-electron transistor/CMOS hybrid technology for biomedical applications

Lee, Jieun,Choi, Changmin,Park, Sungwook,Chung, In-Young,Kim, Chang-Joon,Park, Byung-Gook,Kim, Dong Myong,Kim, Dae Hwan Institute of Physics 2009 Semiconductor science and technology Vol.24 No.11

<P>Ultra-energy-efficient analog-to-digital converters (ADCs) based on single-electron transistor (SET)/complementary metal-oxide-semiconductor (CMOS) hybrid technology are proposed as a solution to sense and process biomedical signals. Our results show the energy efficiency of 0.82 pJ/state, which is lower than that in previously reported energy-efficient ADCs. The performance and dissipated power of proposed ADCs are estimated and compared with those of CMOS ADCs by using Lee's SPICE model including non-ideal effects of the experimental data. While the proposed ADC shows an operating power lower by two orders of magnitude than that of the CMOS flash-type ADC, the number of required transistors is about 10% of that in the CMOS flash-type ADC. The peak-to-valley current ratio in Coulomb oscillation of SETs used in the circuit implementation has the range of 1.15–1.5, which is consistent with the experimental result of top-down approached Si-based SETs at <I>T</I> = 77–100 K. From the perspective of the immunity to the gate capacitance <I>C<SUB>cg</SUB></I> mismatch and the background charge <I>Q</I><SUB>0</SUB> noise, it is shown that the criteria of SET/CMOS hybrid ADCs are Δ<I>C<SUB>cg</SUB></I> ⩽ 0.02 × <I>C<SUB>cg</SUB></I> (with <I>C<SUB>cg</SUB></I> = 0.24 aF) and Δ<I>Q</I><SUB>0</SUB> ⩽ 0.23<I>q</I>, respectively.</P>

종합병원 입원 환자에서의 불면증의 임상적 특징

이종국,유태혁,한창환 大韓神經精神醫學會 1991 신경정신의학 Vol.30 No.1

The purpose of this study is to investigate the clinical characteristics of insomnia in 300 new inpatients of general hospital with semistructured interview and questionaires. Among 4 clinical groups-129 noninsomniacs, 171 insomniacs (100 insomniacs with past insomnia history and 71 without past history), we compared the following variables ; age, sex, associated significant diseases, usual life habits, environmental variables influencing sleep pattern, types of insomnia, causes of insomnia, coping methods with insomnia, and usage of hypnotics. In insomniacs we also compared the changes of types and causes of insomnia, coping methods with insomnia after admission. The prevalence of insomnia was significantly increased after admission, and was higher in female patients but not significantly different in age. The frequencies of associated significant disease(angina, arrhythmia, asthma, duodenal ulcer etc.), naps, smoking, alcohol and coffee drinking showed no difference between insomniacs and noninsomniacs. Among environmental variables, “apprehension about illness”, “noise”, “nurse's visit”, and “bed discomfort”were significantly more frequent in insomniacs. Presence or absence of past insomnia history gave no significant effect on the types, causes of insomnia and coping methods with insomnia. Difficulty in maintaining sleep(DMS) was significantly increased after admission but difficulty in falling asleep(DFA) was decreased. The causes of insomnia were physical illness, sleep environmental variables, and psychological variables in order ; first two of these were significantly increased after admission. After admission as well as before admission, the most coping method with insomnia was “effort to forget problems”. Among the methods, “exercise or walking” was significantly increased after admission. Afterwards the study on the psychopathology and characteristics of personality which related with insomnia will be needed to broaden our understanding about insomnia and to establish proper management plan of insomnia.

텅스텐인산으로 개질된 SBA-15 촉매 상에서 아세트산의 탈수반응

우창수,He, Nong-Yue,김현국,이호인 한국공업화학회 2004 응용화학 Vol.8 No.1

TPA (tungstophosphoric acid), a typical heteropoly acid, was impregnated on SBA-15 to modify the acidic property of the mesoporous catalyst. The TPA was highly dispersed on the SBA-15 which has large surface area confirming by nitrogen adsorption, X-ray diffraction, and infrared spectroscopy. According to the result of in-situ FTIR spectroscopy using pyridine as a probe molecule, it was revealed that silanol group was gradually decreased with increasing the loading amount of TPA, and that new acidic site different from that of pure TPA was generated resulting in the enhancement of catalytic activity. TPA could act as a promoter when loaded on SBA-15 by relatively small amount, but the catalytic activity was greatly decreased due to the loss of silanol group as an active site when a large amount of TPA was loaded.

알루미늄과 헤테로폴리산으로 개질된 메조포러스 실리카 상에서의 AKD 합성

김현국,우창수,최재석,박민태,이병민,이호인 한국공업화학회 2003 응용화학 Vol.7 No.1

AKD(alkyl ketene dimer) used widely as a neutral sizing agent is produced industrially by halogenization of stearic acid followed by dimerization of alkyl ketene. In the present work, to suppress the byproduct of hydrochloric acid and to improve reaction pathway. AKD was prepared through of ketene intermediate by dehydration of stearic acid in gas phase using reaction with silanol on silica as active sites of the catalyst SBA-15 showed the highest activity due to the large and open tubular pores. It was found that main products were dimer and trimer. Our goal of the present work was to increase of the selectivity for the dimer.

약물을 이용한 의식진정시 발생한 부작용에 대한 치험례

한국재,이창섭,이상호,김현식 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.4

The patients visiting pediatric dental office have been being younger than the previous, and they were often combined with systemic disease. But, we aren't able to perform the verbal communication, because of their impediment and youthfullness. And, we can't carry out the behavior control via physical restraint, as the developed social structure and the attitude of children and their parents. So, the importance and concerning of conscious sedation using sedative medicine are increased by time and time. Among the various conscious sedation, Chloral Hydrate and Nitrous Oxide inhalation are most popularly used, and barbiturates, benzodiazepine, opioids and hydroxyzine are used often. But, these medications have some side-effects and adverse reactions, may be failed to sedate the children. And limited use of medically compromised patients, especially for ASA class Ⅲ, Ⅳ or more dangerous patients. We, the Department of Pediatric Dentistry, Chosun University have met some dangerous situation due to unfavorable pharmacogenic reactions, but we can control the situation and get well healed results. The below results are common situations and their solutions during conscious sedation. 1. By the intravenous administration, thrombophlebitis is the most common side-effects, but it may be healed with time without any special treatment. 2. Under the definitive guidelines about conscious-sedation, we can perform a safe conscious sedation for ASA class Ⅲ patients. 3. When adversed reaction of Benzodiazepine is occured, it could be cared effectively with benzodiazepine antagonist, named Flumazenil.

酸棗仁이 CT105에 의한 신경세포 상해 및 白鼠의 기억에 미치는 영향

정정욱,박창국,박치상,이소연,윤현덕,신오철 대한본초학회 2005 大韓本草學會誌 Vol.20 No.1

Objective: This study was designed to research whether demonstrate neuroprotective and memory enhancing effects of Z1BU, suggesting its beneficial actions for the treatment of AD. Methods: The present study investigated effects of the dichloromethane extract of Semen Zizyphi Spinosae(ZIBU) on neurotoxicity and reactive oxygen species(ROS) and nitric oxide(NO) formation in PC 12 cell line overexpressed with carboxyl-terminal 105 amino acid peptide fragment of amyloid precursor protein(CT105). In addition, the present study evaluated its radical scavenging activity and effects on acetylcholinesterase(AChE) activity. Furthermore, effects on neuronal loss in CAl area and cognitive deficits induced by scopolamine treatment were also evaluated in rats. Result: we found in this study that ZIBU significantly inhibited apoptotic neuronal death induced by CT105 overexpression in PC12 cells, with the IC_(50) value of 23 ㎍/ml. Based on phase-contrast and fluorescence microscopic examinations, ZIBU reversed morphological changes of CT105-expressed PC-12 cells. It was also found that Z1BU significantly induced neurite outgrowth and inhibited formation of ROS and NO.Z1BU scavenged DPPH radicals and inhibited AChE activity. Furthermore, it attenuated memory impairment induced by the injection of scopolamine in rats, based on passive avoidance test. Crystal violet staining of rat brain slices exhibited increase in the viability of pyramidal neurons in hippocampal CAI area. Conclusion: these results demonstrate neuroprotective and memory enhancing effects of ZIBU, suggesting its beneficial actions for the treatment of AD.

Comparison of Pyrolysis Patterns of Different Tobacco Leaves by Double-Shot Pyrolysis-GC/MSD Method

Lee, Chang-Gook,Lee, Jae-Gon,Jang, Hee-Jin,Kwon, Young-Ju,Lee, Jang-Mi,Kwag, Jae-Jin,Kim, Soo-Ho,Sung, Yong-Joo,Shin, Chang-Ho,Kim, Kun-Soo,Rhee, Moon-Soo The Korean Society of Tobacco Science 2008 한국연초학회지 Vol.30 No.2

In this paper, we describe our study on the characterization of tobacco leaves by their pyrolysis patterns. Two kinds of tobacco leaves were pyrolyzed and analyzed by Double-Shot Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS) methods. Three grades of Korean flue-cured tobacco leafsuch as B1O, AB3O, CD3L and burley tobacco leaves such as B1T, AB3T, CD3W were pyrolyzed with six discrete but stepwise heating temperature ranges, those are from 100$^{\circ}C$ to 150$^{\circ}C$, 150$^{\circ}C$ to 200$^{\circ}C$, 200$^{\circ}C$ to 250$^{\circ}C$, 250$^{\circ}C$ to 300$^{\circ}C$, 300$^{\circ}C$ to 350$^{\circ}C$ and finally from 350$^{\circ}C$ to 400$^{\circ}C$. Using the resultant 52 pyrolytic components identified in the programs as components, principal component analysis (PCA) showed statistical classification between flue-cured and burley tobacco lamina. Among six pyrolysis temperature ranges, the best discrimination was achieved at the temperature range from 250$^{\circ}C$ to 300$^{\circ}C$ and from 300$^{\circ}C$ to 350$^{\circ}C$.

휴경논 토양 및 수질 변화

강종국 ( Jong Gook Kang ),정지호 ( Ji Ho Jeong ),이경보 ( Kyeong Bo Lee ),양창휴 ( Chang Hyu Yang ),이경도 ( Kyeng Do Lee ),김재덕 ( Jae Duk Kim ) 한국토양비료학회 2007 한국토양비료학회 학술발표회 Vol.2007 No.1

면역기능이 정상인 사람에서 거대세포 바이러스 감염에 의한 소장궤양 출혈

이상인,박인서,최성우,박효진,이창훈,김동주,이세준,박영년,이관식,정준표,송영구,추적금,손승국 대한소화기학회 2000 대한소화기학회지 Vol.36 No.5

Cytomegalovirus (CMV) infections are commonly reported in immunocompromised hosts and ulcers of the alimentary tract are frequently observed in patients with systemic CMV infection. However, many reports show that CMV infection can produce localized ulcerations in the esophagus, stomach, small intestine, and colon of immunocompetent individuals. The common site involved by CMV infection in the gastrointestinal (GI) tract is the colon, which is followed by upper GI tract. The case in which CMV infection involves the small intestine is rare. Although GI bleeding is one of the major symptoms of patients with CMV infections in the GI tract, lower GI bleeding due to CMV ileal ulcers in immunocompetent patients has not been reported yet. Recently, we experienced a case of lower GI bleeding due to CMV ileal ulcers in a healthy 57-year-old man. This case suggests that small intestinal ulcers by CMV infection may be considered to cause lower GI bleeding even in immunocompetent hosts.

A High Voltage NMOSFET Fabricated by using a Standard CMOS Logic Process as a Pixel-driving Transistor for the OLED on the Silicon Substrate

Lee, Cheon-An,Jin, Sung-Hun,Kwon, Hyuck-In,Cho, Il-Whan,Kong, Ji-Hye,Lee, Chang-Ju,Lee, Myung-Won,Kyung, Jae-Woo,Lee, Jong-Duk,Park, Byung-Gook The Korean Infomation Display Society 2004 Journal of information display Vol.5 No.1

A high voltage NMOSFET is proposed to drive top emission organic light emitting device (OLED) used in the organic electroluminescent (EL) display on the single crystal silicon substrate. The high voltage NMOSFET can be fabricated by utilizing a simple layout technique with a standard CMOS logic process. It is clearly shown that the maximum supply voltage ($V_{DD}$) required for the pixel-driving transistor could reach 45 V through analytic and experimental methods. The high voltage NMOSFET was fabricated by using a standard 1.5 ${\mu}m$, 5 V CMOS logic process. From the measurements, we confirmed that the high voltage NMOSFET could sustain the excellent saturation characteristic up to 50 V without breakdown phenomena.