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>

Mg-Fe 산화물계 NTC 서미스터의 特性

오영우,김현식,허정섭,이승관 경남대학교 신소재연구소 1997 論文集 Vol.9 No.-

조정식 Mg₁-χFe₂+χO₄(이하 Mg계)에서 x를 0.0, 0.025, 0.1, 0.2로 변화시키고, 소결온도를 1100°C~1250°C로 50°C간격으로 변화시켰다. 그 결과, NTC 서미스터의 특성을 잘 나타내었고, 저항온도계수 α는 Mg계일 때 -1.6%/°C로 높은 값을 나타내었고, B정수는 1500 [K]에서 2920 [K]의 범위를 나타내었다. 본 조성의 실험결과로써 Mn-Ni-Co계 서미스터를 Mg-Fe 산화물계 NTC 서미스터로 대체가 가능함을 확인할 수 있었다. Mg_{1-x}Fe_{2+x}O₄was prepared by sintering at from 1100℃ to 1250℃ with 50 C intervals, while x was varied from 0.0 to 0.025. 0.1, and 0.2. The results showed the typical properties of NTC(Negative Temperature Coefficient) thermistor. The best temperature coefficient of resistance, α was -1.6%/℃ in the Mg-based sample at 25 C. Thermistor parameter, B was in the range of 1500 [K]∼2920 [K]. As a result, the possibility that Mn-Ni-Co based thermistor could be substituted by the composition used in this study was confirmed.

이익관리연구에 관한 개관 : 1980-1990년대 연구를 중심으로

장석오,노현섭 한국세무회계학회 2003 세무회계연구 Vol.12 No.-

본 연구는 이익관리에 대한 증거와 그 증거가 회계연구자들에 대한 함의를 검토하고 이익관리에 대한 가능한 미래연구 분야를 개관한다. 전반적으로, 대부분의 선행연구들은 이익관리가 존재하는지의 여부와 이익관리가 행해지는 이유에 대해서만 초점을 맞추고 있다. 선행연구의 결과는 이익관리가 주식시장의 인지에 영향을 미치기 위하여, 경영자의 보상을 증가시키기 위하여, 차입계약의 위반가능성을 감소시키기 위하여, 그리고 규제적 개입을 회피하기 위한 목적 등을 포함한 다양한 동기에서 수행되고 있다는 것을 시사해 준다. 본 연구의 검토결과가 갖는 한가지 함의는 이익관리의 존재여부에 대한 보다 강력한 검정으로부터 얻어질 가능성은 적은 반면, 회계상의 재량이 이익관리에 얼마나 빈번하게 사용되는지 그리고 이러한 행위가 이익에 얼마나 많은 영향을 미치는지에 대한 연구에서 미래의 공헌점이 얻어질 것으로 생각된다. 또한, 경제에서 이익관리가 주가와 자원배분에 미치는 영향에 대한 상반된 결과를 더욱 일치시키는 것이 필요할 것으로 생각된다.

제타 포텐셜과 레올로지 측정을 통한 최적의 Y-TZP/Mullite 슬러리 안정성과 분말의 분산 : Optimization with Zeta Potential and Rheological Measurements

박우경,전병세,--,--,--,-- 경남대학교 신소재연구소 1999 論文集 Vol.11 No.-

가압 여과(Filter pressing)에 의한 Y-TZP/Mullite 세라믹 복합체의 제조를 위하여 슬러리의 분산거동을 살펴보았다. 각 조성에 해당하는 현탁액의 분산안정성을 살펴보기 위하여 분산제(NaHMP) 함량을 각각 0~1 wt.% 첨가시켜 pH 변화와 제타 전위를 측정하였다. 그 결과, Y-TZP, 그리고 Mullite는 분산제의 함량을 각각 0.5 wt.%, 그리고 0.8 wt.% 첨가하였을 때 최적의 분산 조건이 형성되었으며, 이 때의 pH 값은 8(±0.2) 이었다. 또한 Y-TZP/Mullite 혼합 현탁액에서 최적의 분산조건은 0.6 wt.% (pH 8.2)이다. 각 현탁액의 최적의 분산조건에서 고체함량을 20 vol.%로 한 Y-TZP/Mullite 현탁액에 결합제 함량이 약 0.15 wt.% 일 때, 가압 여과에 적절한 점도값인 100 cps를 나타내었다. Y-TZP/Mullite Slurries Stability by Filter Pressing were investigated. For the stable suspensions consisting of Y-TZP and Mullite. were examined dispersion behavior and viscosity measurement. A dispersing agent (NaHMP) was changed from 0 to 1 wt.%. and then pH and zeta potential was measured. As a result of examinations, the optimal contents of the dispersing agent for Y-TZP, and Mullite were 0.5 wt.%. and 0.8 wt.% respectively. and the pH values were around 8 (±0.2) . The optimal contents of the dispersing agent for Y-TZP/Mullite were 0.6 wt.%(pH 8.2). Optimal binder content of Y-TZP/ Mullite slurry for filter pressing was 0.15 wt.% and viscosity was 100 cps when the solid loading was 20 vol.%

COM 기반의 웹 DB 접근 설계 및 구현

박상훈,박진섭,권오현 대전대학교 산업기술연구소 2000 산업기술연구소 論文集 Vol.11 No.2

This era is approached that the dynamic web server survives which is interacting with database. And also a lot of studies about minimizing the cost and properly updating softwares in time is carried out. COM(Component Object Model) is recently one of the software development methodology In many case, ODBC(Open Database Connectivity) drivers are used in web database design. But some problems cannot be solved by the ODBC. These problems can be solved by COM which is the concept of the component. We approached to the web database access using COM, In this paper we provide detailed interface modeling of web database. The interface modeling provided consists of COM Client. Web server, Com Server and can show the client the result of what he want to insert by SQL statements.

최적설계 기법을 적용한 1톤 운반차용 P.T.O축 및 트랜스미션 개발에 관한 기초연구

김재열,심재기,최승현,정효희,김훈조,오현중,박경섭 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

Now, power tillers and cultivators which are spread among fruit tree households have usage, low application, and high accident risk. Therefore, the development of multi-purpose work vehicles is needed as an alternative for these problems. Especially, easy usage and the ability to easily change gears when driving and the development of the P.T.O for various tasks such as pruning, water lifting, pest control, application and, mowing are needed. In this research, we will develop a transmission with design on P.T.Oaxle for agricultural work vehicles including multi-purpose vehicles. We aim to develop a 4-wheel drive transmission of synchronous contact type for practical use in fruit tree households which is required to be a large-sized agricultural vehicle. Therefore, we have per performed as follows that are composed of load capacity from 500kg to 1,000kg, safety securing for passengers, and drive securing under bad conditions of the topography slope and swampy land and the rest. For this purpose, we have developed a prototype vehicle through strength analysis of transmission design. we have selected optimal design conditions (Optimal RPM and torque according to some works) on the power transmission with multi-purpose vehicle for various jobs: spraying, manure spreading, mowing, brush wood chopping. If development of the P.T.O containing variable RPM and torque is successful, the following tasks can be possible. Air pruning, air maintenance, water lift, pest control, application, mowing, spraying, and brush wood chopping are possible with this developed P.T.O. Methods and contents for research are followed. Therefore, we have achieved performance-tests through the prototype of the multi-purpose work vehicle and have improved on troubles by the analysis of results of R&D. Also, we provided solutions to problems in mass production in the future.

Synthesis and Anion Recognition Features of a Molecular Cage Containing Both Hydrogen Bond Donors and Acceptors

Oh, Ju Hyun,Kim, Jeong Hyeon,Kim, Dong Sub,Han, Hye Jin,Lynch, Vincent M.,Sessler, Jonathan L.,Kim, Sung Kuk American Chemical Society 2019 Organic letters Vol.21 No.11

<P>A molecular cage, macrobicycle <B>2</B>, containing amide and pyrrole groups as hydrogen-bonding donors and imine groups as hydrogen-bonding acceptors has been synthesized. Compound <B>2</B> was found to recognize tetrahedral oxyanions with high affinities, such as H<SUB>2</SUB>PO<SUB>4</SUB><SUP>-</SUP>, HSO<SUB>4</SUB><SUP>-</SUP>, SO<SUB>4</SUB><SUP>2-</SUP>, and HP<SUB>2</SUB>O<SUB>7</SUB><SUP>3-</SUP>, as well as the spherical halide anions, in chloroform. A single-crystal X-ray diffraction analysis revealed that compound <B>2</B> formed a 1:1 complex with H<SUB>2</SUB>PO<SUB>4</SUB><SUP>-</SUP> in the solid state.</P> [FIG OMISSION]</BR>

Hydrodeoxygenation of oleic acid over Ce<SUB>(1-x)</SUB>Zr<SUB>(x)</SUB>O<SUB>2</SUB> solid solution

Jae-Oh Shim,Dae-Woon Jeong,Won-Jun Jang,Kyung-Won Jeon,Won-Bi Han,Hyun-Suk Na,Hak-Min Kim,Hyun-Seog Roh,Jeong-Geol Na,You-Kwan Oh,Chang Hyun Ko,Sang Sub Han 한국신재생에너지학회 2013 한국신재생에너지학회 학술대회논문집 Vol.2013 No.05

Energy-Band-Engineered Unified-RAM (URAM) Cell on Buried <tex> $\hbox{Si}_{1 - y}\hbox{C}_{y}$</tex> Substrate for Multifunctioning Flash Memory and 1T-DRAM

Jin-Woo Han,Seong-Wan Ryu,Chung-Jin Kim,Sung-Jin Choi,Sungho Kim,Jae-Hyuk Ahn,Dong-Hyun Kim,Kyu Jin Choi,Byung Jin Cho,Jin-Soo Kim,Kwang Hee Kim,Gi-Sung Lee,Jae-Sub Oh,Myeong-Ho Song,Yun Chang Park,Je IEEE 2009 IEEE transactions on electron devices Vol.56 No.4

<P>A band-offset-based unified-RAM (URAM) cell fabricated on a Si/Si<SUB>1-y</SUB>C<SUB>y</SUB> substrate is presented for the fusion of a nonvolatile memory (NVM) and a capacitorless 1T-DRAM. An oxide/nitride/oxide (O/N/O) gate dielectric and a floating-body are combined in a FinFET structure to perform URAM operation in a single transistor. The O/N/O layer is utilized as a charge trap layer for NVM, and the floating-body is used as an excess hole storage node for capacitorless 1T-DRAM. The introduction of a pseudomorphic SiC-based heteroepitaxial layer into the Si substrate provides band offset in a valence band. The FinFET fabricated on the energy-band-engineered Si<SUB>1-y</SUB>C<SUB>y</SUB> substrate allows hole accumulation in the channel for 1T-DRAM. The band-engineered URAM yields a cost-effective process that is compatible with a conventional body-tied FinFET SONOS. The fabricated URAM shows highly reliable NVM and high-speed 1T-DRAM operations in a single memory cell.</P>

Retinal Toxicity of Commercial Tissue Plasminogen Activator Is Mediated by the Induction of Nitric Oxide in the Mouse Retinal Primary Cells

Oh, Hyun-Sub,Kwon, Oh,Chung, In,Lee, Sung,Koh, Hyoung,Lee, Sung-Ho,Lee, Joon Taylor Francis 2005 Current eye research Vol.30 No.4

<P>Purpose: Tissue plasminogen activator (tPA) is an efficient thrombolytic agent, but the dose-dependent retinal toxicity of intravitreal injection of commercial tPA (containing l-arginine) has been reported. Here, we sought to investigate the mechanism of tPA-induced cell death in mouse retinal cell cultures and the role of nitric oxide (NO). Methods: Primary retinal cell cultures were maintained using glial conditioned medium (GCM) solution. Mouse retinal cell death was observed by using Hoechst-propidium iodide staining. Mouse retinal cell death was also measured by lactate dehydrogenase (LDH) assay. The formation of NO was measured using Griess reagent. Results: tPA-induced cell death was detected in mouse retinal cell cultures by Hoechst-propidium iodide staining or LDH assay. l-Arginine seems to be the major factor in retinal toxicity of commercial tPA (containing l-arginine). The formation of NO was markedly increased in mouse retinal cell cultures treated with tPA (containing l-arginine) or l-arginine. NO inhibitor reduced the cell death induced by commercially available tPA or l-arginine. Conclusions: This study suggests that l-arginine from commercial tPA (containing l-arginine) induces the majority of cell death in mouse retinal cell cultures and that its cytotoxicity may depend on the induction of NO.</P>