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.

實驗大學 實施에 따른 師範大學 學生實態

李相魯,林在圭,吳岱燮,閔庚德 慶北大學校 師範大學 1977 敎育硏究誌 Vol.19 No.-

The purposes of this study were (1) to analyze students' reasons, for applying to the Teachers College, department and major; (2) to assess the degree of satisfaction on being assigned to their particular department; (3) to investigate their attitudes toward the new way of assigning students in terms of two broadly classified majors i.e., studies of humanistic and social sciences and studies of natural sciences; (4) to estimate the degree of fulfillment of student desire and degree of utility of physical facilities; and (5) to identify reasons of success or failure of the students in the respective departments they were assigned to. The subjects were 2 groups of Teachers College students, one group which entered the university in 1976 and the other in 1977. In order to collect data pertaining to students' opinions or attitudes, questioniares were used; the score on college entrance exam and grade point average were obtained from individual student reports. The data were statistically analyzed by means of either Z or chi-test. The major findings were as follows: 1. Approximately 41 percent of the freshmen of the Teachers College reported that they decided to enter the Teachers College in order to be teachers. 2. Approximately 70 percent of the Teachers College students decided their particular major by themselves rather than by suggestions or advices. 3. The degree of satisfaction on having entered the Teachers College was relatively high, since the average scale point was .472. 4. The fresh students showed a significant decrease in their positive attitude toward the new way of assigning the students to the department or majors. The average scale point of the students in 1975 was .276; that of in 1976 was .489; that of the students in 1977 was .077. When the changes in attitude toward the new way of assigning students to departments or majors were estimated, it was observed that the degree of those in favor was .489 at the beginning of the first semester, and-.677 at the end of the second semester. However, the degree of satisfaction reported by students after they were assigned to a specific department or major was .732. Therefore, the negative attitude toward the new way of assigning could be interpreted as a reflection of students' anxiety status of rather than an attitude against the new way of assigning the students.

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

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.

A. 高校 科學 (生物·地球科學) 및 數學科 探究學習의 評價模型 定立과 評價紙 開發

李相協,權炳奎,林在圭,孫文求,吳岱燮,楊洪準,梁承榮,姜用熙,林成圭,金正遠,金吉民,兪正在 경북대학교 과학교육연구소 1982 科學敎育硏究誌 Vol.6 No.-

Currently the evaluation of high school science and mathematics learning has been too much knowledge-centered without concerning the inquiring ability or scientific attitude. This study, therefore, was made for the purpose of establishing of evaluation model for high school science (biology and earth science) and mathematics learning and its evaluation items. In this paper, the research was done about three fields, biology, earth science and mathematics. 1. For the biology, the evaluation methods of inquiry learning were studied with the foreign references, and proper evaluation items were suggested. 2. For the earth science, after analizing 5 kinds of earth science textbook of current using in high school, essential 19 items were selected. 5 of them were tested in test group and control group, then, the results were analized. 3. For the mathematice, the teaching elements of「Set」and「Flow chart」in mathematics (Ⅰ) were selected and structured. Detailed teaching objects were established and evaluation items were introduced.

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.

GPS/GPR을 이용한 저수지 준설능력 향상

이재원,이동락,엄장섭 東亞大學校 建設技術硏究所 2008 硏究論文集 Vol.31 No.2

일반적으로 퇴적물 준설에 대한 조사는 GPS/Echo Sounder 및 Total Station/Echo Sounder를 조합하여 대상지의 수평위치 및 수심에 대한 관측을 실시하고 있으며, 하상의 단면계산 저수량 및 준설계획량 등을 추정 이후 준설계획에 대한 계획고 및 준설토량에 대한 세부적인 계획을 수립하게 된다. 하지만 Echo Sounder를 사용하는 음파탐사 방법은 퇴적물에 대한 정확한 분포를 파악할 수 없는 단점이 있다. 본 연구는 저수지 하부의 퇴적물 및 이의 분포를 파악하여 저수지 준설계획을 수립하여 기존의 탐사방법에 대한 준설능력 향상에 중점을 두었으며, 기존의 음파탐사 방식과 다른 레이더탐사 장비를 이용한 GPS/GPR(Ground Penetration Radar)을 사용하여 저수지의 수평위치, 수심값을 결정하고 동시에 원 지반에 분포하고 있는 퇴적물의 분포를 추정, 준설에 적용하고자 하였다. 우선 현장의 시료채취를 통한 수조모형실험을 실시하여 장비에 대한 정확도 검증을 거친 후 현장적용에 적용하여 그 가능성을 평가하였다.

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.