A sub-1-volt nanoelectromechanical switching device.

Lee, Jeong Oen,Song, Yong-Ha,Kim, Min-Wu,Kang, Min-Ho,Oh, Jae-Sub,Yang, Hyun-Ho,Yoon, Jun-Bo Nature Pub. Group 2013 Nature nanotechnology Vol.8 No.1

<P>Nanoelectromechanical (NEM) switches have received widespread attention as promising candidates in the drive to surmount the physical limitations currently faced by complementary metal oxide semiconductor technology. The NEM switch has demonstrated superior characteristics including quasi-zero leakage behaviour, excellent density capability and operation in harsh environments. However, an unacceptably high operating voltage (4-20 V) has posed a major obstacle in the practical use of the NEM switch in low-power integrated circuits. To utilize the NEM switch widely as a core device component in ultralow power applications, the operation voltage needs to be reduced to 1 V or below. However, sub-1 V actuation has not yet been demonstrated because of fabrication difficulties and irreversible switching failure caused by surface adhesion. Here, we report the sub-1 V operation of a NEM switch through the introduction of a novel pipe clip device structure and an effective air gap fabrication technique. This achievement is primarily attributed to the incorporation of a 4-nm-thick air gap, which is the smallest reported so far for a NEM switch generated using a 'top-down' approach. Our structure and process can potentially be utilized in various nanogap-related applications, including NEM switch-based ultralow-power integrated circuits, NEM resonators, nanogap electrodes for scientific research and sensors.</P>

Haplogroup Classification of Korean Cattle Breeds Based on Sequence Variations of mtDNA Control Region

Kim, Jae-Hwan,Lee, Seong-Su,Kim, Seung Chang,Choi, Seong-Bok,Kim, Su-Hyun,Lee, Chang Woo,Jung, Kyoung-Sub,Kim, Eun Sung,Choi, Young-Sun,Kim, Sung-Bok,Kim, Woo Hyun,Cho, Chang-Yeon Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.5

Many studies have reported the frequency and distribution of haplogroups among various cattle breeds for verification of their origins and genetic diversity. In this study, 318 complete sequences of the mtDNA control region from four Korean cattle breeds were used for haplogroup classification. 71 polymorphic sites and 66 haplotypes were found in these sequences. Consistent with the genetic patterns in previous reports, four haplogroups (T1, T2, T3, and T4) were identified in Korean cattle breeds. In addition, T1a, T3a, and T3b sub-haplogroups were classified. In the phylogenetic tree, each haplogroup formed an independent cluster. The frequencies of T3, T4, T1 (containing T1a), and T2 were 66%, 16%, 10%, and 8%, respectively. Especially, the T1 haplogroup contained only one haplotype and a sample. All four haplogroups were found in Chikso, Jeju black and Hanwoo. However, only the T3 and T4 haplogroups appeared in Heugu, and most Chikso populations showed a partial of four haplogroups. These results will be useful for stable conservation and efficient management of Korean cattle breeds.

회선 적분법에 의한 기저유출의 예측

이희주,심현섭,이재형 全北大學校 附設 都市및環境硏究所 2000 都市 및 環境硏究 Vol.15 No.1

The purpose of this study is to predict of base-flow through convolution. The predicting methods in the present are graphical method, method of recession constant and so on. But, graphical method needs many time, and includes subjective errors. Therefore, recession constant is generally using for the prediction of base-flow. However, the predicted base-flow values by this method are on the decrease at a same rate. But, the base-flow reduction rate is changed by the amount of rainfall, initial condition etc. So, to satisfy these conditions, the predicting model using convolution method is used in this study. And base-flow is predicted from initial outflow volume through convolution. In this study, routing constant and characteristic constant consisting the functions is determined, and complete the base-flow predicting model. Afterwards, we compare the predicting value through convolution whit the observed value in the watershed.

교육에서의 WWW 사용 및 구성 환경에 대한 연구

徐鎭亨,李載昊 仁川敎育大學校 科學敎育硏究所 1997 과학교육논총 Vol.9 No.-

WWW (World Wide Web) changed the internet from text based to viewable. According to this, Internet related industries changed rapidly. However, education using WWW is unchanged. Just display the contents as line by line. This kind of environment is not accomplish the objectives of modern educational concept, like view, listen and speech, and cannot utilizes the real things of WWW. In this paper, we review and describe the current internet and WWW environments and future WWW extension of WWW and which kinds of contents added for future education and WWW environments.

12주간 복합운동이 여성 중, 고령자의 신체조성, 혈중변인, 생리적인 변인 및 근력에 미친 효과

이재구,최무섭 한국유산소운동과학회 2003 대한스포츠융합학회지 (jcses) Vol.7 No.1

The purpose of this study was to investigate the comprehensive alterations on body composition, blood profile, physiological variables, and muscle strength, that result from combination of aerobic exercise and muscular endurance training during 12 weeks. Methods in this study; 37 healthy women were involved in subjects. All of them were screened by questionnaire, direct interview, blood profile test, and graded exercise test. They did exercise 3 times sessions per week, programmed with walking and jogging on treadmill and 8 muscular exercises to the local sites of body by free weight instruments. All exercise session have been performed by supervised exercise. Results; Body weight reduced significantly about 1.8kg(p<.05 after 12 weeks. Middle-aged group was higher reduction of body weight than the other groups. However, there were no significant changes on body fat and lean body mass after exercise. blood glucose in fasting reduced significantly after 12 wks(8㎎/dl, p<.01). Significant reductions in total cholesterol(18㎎/dl, p<.01)and triglyceride(39㎎/dl, p<.01)were observed post exercise. In case of muscular strength, eccentric contraction increased sigmficantly 8-9 peak force(p<.05) after 12 wks. but concentric contraction was not after exercise. Physiologic variables such as HR, systolic and diastolic BP, and RPP decreased significantly after exercise, 8 beats/min, 16 ㎜Hg, 9 ㎜Hg, and 4,477 beats/min-㎜Hg, respectively. and exercise duration time on treadmill was longer 15%(p<.05) than that of pe-exercise. In conclusion, combine exercise program in this study is effective exercise modality to improve blood profile, physiologic variable, and muscle strength among middle-aged and elder women.

16주간 근력운동에 따른 국소부위 골밀도의 변화와 상관관계 특성

이재구,최무섭 한국유산소운동과학회 2002 대한스포츠융합학회지 (jcses) Vol.6 No.1

This study was performed to suggest the effects of mild strength exercise on local bone densities and the correlation characteristics among the various variables, body composition and local bone densities, in middle-aged women. The subjects were volunteered in 16 women being resident in the local community. Their ages were within 47.6±4.8 years. Body composition were analyzed by the Bioelectrical Impedence method(mode1; In Body.1999, Biospace Co. Korea), and local bone densities were measured by DEXA method(PIXI 5108 model, Lunar Co. USA). All subjects performed mild strength exercise, 3 timedweek during 16 weeks, Exercise session were constructured into warm up by walking and stretching 20min. and muscle training on the sites that measure the bone densities during 30 minutes. Results in this study were as following. Body compositions were significantly reduced in muscle volume 2.6% and body fat 3.63% after 16weeks . Local bone densities in the forearm were nonsignificantly 0.73% at 1/3 site and 1.24% at middle site, and ulna distal site was significantly decreased in 4.51% after 16wks. but total bone density in the forearm was reduced 1.4% nonsinificantly in the postexercise. Lumbar site was, also, increased 0.4% without significance at lumbar 2-4 level. All of three femoral sites, however, did increased nonsignificantly 1.58% at neck, 1.06% at greater trochanter, and 5.62% at ward's triangle in the postexercise. Serum calcium and osteocalcin values were significantly higher 13.7%(P=0.0000)and 54.1%(0.01) than before. Weight variable was significantly correlated with a bone density at a femoral neck site(r=0,34,P=0.05) and BMI had the significant correlation with neck(r=0.43,P=0.01) and greater trochanter(r=.44, P=0.01) in femur. Correlation characteristic among local bone densities appeared higher(r=0.41-0.71, P=0.01) between the lumbar and femur sites than those(r=0.38, P=0.02) between the lumbar and forearm sites. there was middle level(r=0.45-0.58, P=0.001.)between forearm and femur site. In conclusion, it was suggested that local bone density in middle-aged women can be increase through mild strength exercise over mechanical stress of ordinary lifestyle during 16 weeks.

세로토닌성 항우울제가 백서의 Schedule-Induced Polydipsia에 미치는 영향

이기철,이정호,박중섭,최영민,전성일,정홍경,하준명,정재현 대한생물치료정신의학회 1999 생물치료정신의학 Vol.5 No.2

Object : Schedule-induced polydipsia is considered as an animal model of obsessive-compulsive disorder inrats. The authors evaluated the chronic effects of fluoxetine and clomipramine as serotonergic antidepressants and haloperidol as dopaminergic antagonist on the schedule-induced polydipsia in rat.Methods : Spraque-Dawley rats weighing 200-250gm were individually housed, maintained and allowed free access to water for 1 week. And then the rats were placed on a restricted diet. To induce polydipsia, rats were placed in automatic cage where a pellet dispenser automatically dispensed 90mg pellets on a fixed-time 60 seconds(FT 60s) feeding schedule over 150-minute test session for a day. Water was available at all times during the feeding schedule in automatic cage. After 4 weeks of daily exposure to the FT 60s feeding schedule, experimental rats met a predetermined criterion for polydipsic behavior(greater than 3 times of water per session on average). 4 groups of rats were administered fluoxetine(5mg/kg/i.p.), clomipramine(5mg/kg/i.p.), haloperidol(0.1mg/kg/i.p.), vehicle(1cc/kg/i.p.) for 3 weeks. Rats were tested once a week to access schedule induced polydipsic behavior. The chronic effects of experimental drugs on schedule induced polydipsic behavior were analyzed with repeated analysis of variance and Scheffe test as a post-hoc comparison.In order to measure water consumption in non-polydipsic food-deprived rats, a separate group of rats(N=8) were individually housed and given a single bolus(14.5 gm) of food per day which maintained them at their average body weight.Results and Conclusion : The results were as follows ;1) After 4 weeks of daily feeding procedure with fixed time schedule for 60 seconds per day, the experimental group showed significant differences than the control in the amount of water consumption as compared with their baseline water intakes. At the same periods, there were no differences between the experimental group and the control in body weight. 2) The clomipramine treated group and the fluoxetine treated group showed significant decrease in the amount of water intake as compared with their baseline of polydipsic water intakes for 3 weeks of treatment. However, the haloperidol treated group and the vehicle control group showed no changes of amounts of water intake for 3 weeks of treatment as compared with their baseline of polydipsic water intakes. 3) At 2 weeks of drug treatment, clmipramine treated group(16.88±6.51ml) and the fluoxetine treated group(22.50±10.35ml) showed significantly lower amounts of water intake than the haloperidol treated group (41.25±7.06ml) or vehicle control group(37.50±12.54ml). And also the clomipramine treated group(13.75±5.18ml) and the fluoxetine treated group(18.75±3.54ml) showed significantly lower amounts of water intake than the haloperidol group(35.00±11.65ml) and the vehicle control(34.38±6.78ml) at 3 weeks of drug treatment. Above findings suggest that the fixed time feeding procedure for schedule-induced polydipsia as an animal model of obsessive compulsive disorder was effective to the evaluation of pharmacological challenge study. The author confirmed that schedule-induced polydipsia was successfully decreased for 3 weeks of administration of clomipramine and fluoxetine but there was no response to haloperidol.

敎育實習을 通한 授業體制改善의 實踐的 硏究 : 指導案樣式의 開發 Centered on Lesson Plan Format

李慶燮,林在圭,琴種友,鄭浩杓 慶北大學校 師範大學 1979 敎育硏究誌 Vol.21 No.-

This study was undertaken to construct a lesson plan format appropriate for our educational status. To achieve this aim, the following two processes were pursued: first, to investigate the relation between curriculum and lesson plan format; second, to analyze and discuss the lesson plan model used practically in American Schools. Instructional objectives, Structure of contents, instructional processes, and width of instruction are regarded as the fundamental elements of proper lesson plans by this investigation. In terms of theoretical ground about each of the above-mentioned elements, the following lesson plan format, which can be put to a practical use in our educational status, was constructed.

중장년층에서의 외상성 견관절 탈구

이광원,류창수,김하용,안재훈,염진섭,김환정,최원식 대한견.주관절학회 2000 大韓肩.주關節學會誌 Vol.3 No.2

생쥐 대장 평활근 세포에서 내향 정류성 칼륨 전류의 특성 연구

이은주,김명,정명섭,조향훈,김기훈,하현철,김준수,최석,전제열 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Objectives: K^(+) channels play an important role in regulating cellular excitability. The aim of this study was to know whether or not inward rectifier K^(+) channel exists in colonic smooth muscle cells. Methods: Mouse colonic smooth muscle cells were isolated using collagenase, and then we recorded their membrane currents using a whole-cell patch clamp technique. Results: With 90 mM K^(+) in bath, hyperpolarization-induced inward currents from -120 mV to 20 mV with 400 ms duration at a holding potential of -10 mV showed rapid activation, inactivation and inward rectification. The inactivation showed single exponential time course. Reduction of external K^(+) to 60 mM decreased the amplitudes of the currents in whole test voltage range and shifted the reversal potential to more negative potential. The inactivation process and peak currents of hyperpolarization-induced inward currents were not affected by removing external Na^(+). External Ba^(+) blocked hyperpolarization-induced inward currents by dose-dependent manner and pure Ba^(+)-sensitive currents showed strong inward rectification. Cs^(+) also suppressed hyper- polarization-induced inward currents. Ba^(+) and Cs^(+)-induced inhibitiOn of hyperpolarization-induced inward currents was voltage-dependent, and the extent of inhibition increasing with membrane hyperpolarization. Conclusions: These results suggest that inward rectifier KU channels may exist in proximal colonic smooth muscle and may play an important role in regulating membrane potential.