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>

토지은행의 토지비축 효과에 대한 실증분석연구

장인석(In Seok Chang),임주호(Joo Ho Rhim),신형섭(Hyung Sub Shin),송기욱(Ki Wook Song),김미숙(Mi Sook Kim) 한국부동산학회 2023 不動産學報 Vol.89 No.-

우리나라 토지은행 제도는 토지시장 안정을 위해 토지를 사전비축하고, 이를 적시에 공급하는 국가차원의토지수급정책 유형이다. 이 논문은 실제 비축토지를 이용한 5개 단지조성사업과 10개 도로건설사업을 대상으로나누어 공익개발사업에서 토지은행에 의한 비축토지 공급의 당위성 여부와 토지보상비 절감에 어느 정도 기여할수 있는지를 실증분석 한 것이다. 연구결과는 다음과 요약할 수 있다. 첫째, 단지조성사업에서는 토지의 사전비축당위성이 불분명한데 반해, 도로건설사업에서는 토지의 사전비축 당위성이 존재하는 것으로 나타나 사업유형별차이가 있음을 입증하였다. 둘째, 도로건설사업에서는 비축토지의 일괄비축(일괄보상)을 가정할 경우, 평균 6.8% 의 토지보상비 절감이 가능한 것으로 추정되었다. 이와 같은 토지비축의 경제적 효과에 대한 실증분석결과는향후 도시재생수요 및 빈집증가 등에 대한 토지은행 대상 범위확장 시, 사업유형별 토지확보 방식의 차별화를위해 활용할 수 있을 것이다. 1. CONTENTS (1) RESEARCH OBJECTIVES In this study, the necessity and the cost saving effect of preemptive land stockpiling were evaluated for road construction and land development projects.. (2) RESEARCH METHOD This study conducted a qualitative survey on the operation of land banks in Korea and an empirical analysis on the difference between the unit cost of land compensation and the change in land price of surrounding areas during project period. For 5 land development projects and 10 road construction projects, the actual land compensation cost expenditures were compared with the estimated costs assuming lump-sum compensation at the initial point of time. (3) RESEARCH FINDINGS Since the correlation between the published price of land and the unit cost of land compensation, which are changing anually, was unclear in land development projects, the expendture patterns of purchasing land hardly justify the cost-saving effect of preemptive lump-sum compensation. However, in road construction projects, the annual variations in unit cost of land compensation showed similar patterns to the increase in published land price. 2. RESULTS The land stockpiling by land bank is a policy tool to promote public projects such as road construction and industrial complex development quickly by securing land in advance and saving costs. The result showed that, in 10 road construction projects, about 6.8% of land compensation costs can be reduced by assuming lump-sum land purchase in early stages by the Land Bank, while we cannot expect these cost-saving effects in land development projects. It seems that the lump-sum compensation method for stockpiling land is relatively effective in road construction projects, rather than in land development projects, considering the land price increase invoked by development projects. In land development projects, with a proper division of sub-areas to be purchased stepwise, even sequential compensation can be appropriate.

The Variation of Structure and Transporting Property in SrRu_1-xFe_xO₃

Park, Jung-Chul,Kim, Don,Lee, Choong-Sub,Byeon, Song-Ho Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.5

Evidence of reversible oxygen participation in anomalously high capacity Li- and Mn-rich cathodes for Li-ion batteries

Muhammad, Shoaib,Kim, Hyunchul,Kim, Yunok,Kim, Donghwi,Song, Jay Hyok,Yoon, Jaegu,Park, Jin-Hwan,Ahn, Sung-Jin,Kang, Sun-Ho,Thackeray, Michael M.,Yoon, Won-Sub Elsevier 2016 Nano energy Vol.21 No.-

<P><B>Abstract</B></P> <P>The reaction mechanism of a high capacity lithium- and manganese-rich metal oxide, 0.4Li<SUB>2</SUB>MnO<SUB>3</SUB>–0.6LiMn<SUB>0.5</SUB>Ni<SUB>0.5</SUB>O<SUB>2</SUB>, has been investigated at the atomic level. High-resolution synchrotron X-ray powder diffraction (HRPD) and X-ray absorption spectroscopy (XAS) were used, respectively, to evaluate the electrochemical charge and discharge reactions in terms of local and bulk structural changes, and variations in the oxidation states of the transition metal ions. Ni K-edge XAS data indicate the participation of nickel in reversible redox reactions, whereas Mn K-edge absorption spectra show that the manganese ions do not participate in the electrochemical reactions. Rietveld refinements of the oxygen occupancy during charge and discharge provide evidence of reversible oxygen release and re-accommodation by the host structure; this unique oxygen participation is likely the main reason for the anomalously high capacity of these electrodes. The HRPD data also show that during the early cycles, characteristic peaks of the Li<SUB>2</SUB>MnO<SUB>3</SUB> component disappear when charged to 4.7V, but reappear on discharge to 2.5V, consistent with a reversible lithium and oxygen extraction process. The results provide new insights into the charge compensation mechanisms that occur when high capacity, lithium- and manganese-rich electrode materials are electrochemically cycled – a topic that is currently being hotly debated in the literature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Anomalous high capacity of Li- and Mn-rich electrodes has been probed by HRPD and XAS. </LI> <LI> Reversible oxygen release and re-accommodation by the host structure accounts, at least in part, for the unusual high capacity. </LI> <LI> The Li<SUB>2</SUB>MnO<SUB>3</SUB> character of Li- and Mn-rich metal oxide structures is preserved during the initial cycles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Correlations of 3T DCE-MRI Quantitative Parameters with Microvessel Density in a Human-Colorectal-Cancer Xenograft Mouse Model

Ahn, Sung Jun,An, Chan Sik,Koom, Woong Sub,Song, Ho-Taek,Suh, Jin-Suck The Korean Society of Radiology 2011 KOREAN JOURNAL OF RADIOLOGY Vol.12 No.6

<P><B>Objective</B></P><P>To investigate the correlation between quantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) parameters and microvascular density (MVD) in a human-colon-cancer xenograft mouse model using 3 Tesla MRI.</P><P><B>Materials and Methods</B></P><P>A human-colon-cancer xenograft model was produced by subcutaneously inoculating 1 × 10<SUP>6</SUP> DLD-1 human-colon-cancer cells into the right hind limbs of 10 mice. The tumors were allowed to grow for two weeks and then assessed using MRI. DCE-MRI was performed by tail vein injection of 0.3 mmol/kg of gadolinium. A region of interest (ROI) was drawn at the midpoints along the z-axes of the tumors, and a Tofts model analysis was performed. The quantitative parameters (K<SUP>trans</SUP>, K<SUB>ep</SUB> and V<SUB>e</SUB>) from the whole transverse ROI and the hotspot ROI of the tumor were calculated. Immunohistochemical microvessel staining was performed and analyzed according to Weidner's criteria at the corresponding MRI sections. Additional Hematoxylin and Eosin staining was performed to evaluate tumor necrosis. The Mann-Whitney test and Spearman's rho correlation analysis were performed to prove the existence of a correlation between the quantitative parameters, necrosis, and MVD.</P><P><B>Results</B></P><P>Whole transverse ROI of the tumor showed no significant relationship between the MVD values and quantitative DCE-MRI parameters. In the hotspot ROI, there was a difference in MVD between low and high group of K<SUP>trans</SUP> and K<SUB>ep</SUB> that had marginally statistical significance (<I>ps</I> = 0.06 and 0.07, respectively). Also, K<SUP>trans</SUP> and K<SUB>ep</SUB> were found to have an inverse relationship with MVD (<I>r</I> = -0.61, <I>p</I> = 0.06 in K<SUP>trans</SUP>; <I>r</I> = -0.60, <I>p</I> = 0.07 in K<SUB>ep</SUB>).</P><P><B>Conclusion</B></P><P>Quantitative analysis of T1-weighted DCE-MRI using hotspot ROI may provide a better histologic match than whole transverse section ROI. Within the hotspots, K<SUP>trans</SUP> and K<SUB>ep</SUB> tend to have a reverse correlation with MVD in this colon cancer mouse model.</P>

SONOS-Type Flash Memory with HfO₂ Thinner than 4nm as Trapping Layer Using Atomic Layer Deposition

OH, Jae Sub,CHOI, Kwang Il,KIM, Young Su,KANG, Min Ho,SONG, Myeong Ho,LIM, Sung Kyu,YOO, Dong Eun,PARK, Jeong Gyu,LEE, Hi Deok,LEE, Ga Won The Institute of Electronics, Information and Comm 2010 IEICE transactions on electronics Vol.93 No.5

<P>A HfO<SUB>2</SUB> as the charge-storage layer with the physical thickness thinner than 4nm in silicon-oxide-high-<I>k</I> oxide-oxide-silicon (SOHOS) flash memory was investigated. Compared to the conventional silicon-oxide-nitride-oxide-silicon (SONOS) flash memory, the SOHOS shows the slow operational speed and exhibits the poorer retention characteristics. These are attributed to the thin physical thickness below 4nm and the crystallization of the HfO<SUB>2</SUB> to contribute the lateral migration of the trapped charge in the trapping layer during high temperature annealing process.</P>

Mossbauer Spectroscopic Study of La_2-2xSr_2xCu_1-xFe_xO_4-y(0≤x≤0.5) Solid-solution

Park, Jung-Chul,Byeon, Song-Ho,Kim, Don,Lee, Choong-Sub Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.1

Tetragonal $K_2NiF_4$-type $La_{2-2x}Sr_{2x}Cu_{1-x}Fe_xO_{4-y}$ solid-solution have been synthesized by citrate based sol-gel method. The valence state of iron was determined by Mossbauer spectroscopy and subsequent iodometric titration clearly showed that the copper ions in this solid-solution are in the mixed valence state Cu(II/III). When x ${\geq}$ 0.3, Fe(III) is competing with the mixture of Cu(II) and Cu(III) and $La_{2-2x}Sr_{2x}Cu_{1-x}Fe_xO_{4-y}$ exhibits a metallic character. No evidence for Cu(II)-O-Fe(IV) ${\leftrightarrow}$ Cu(III)-O-Fe(III) valence degeneracy was observed. In contrast, a small amount of Fe(IV) is observed with increasing x (x = 0.4 and 0.5), revealing a semiconducting behavior. These results suggest that the electronic interaction of Cu(III)-O-Fe(III) contributes greatly to the metallic character, while the electronic interaction of Cu(II)-O-Fe(IV) deteriorates the metallic character of $La_{2-2x}Sr_{2x}Cu_{1-x}Fe_xO_{4-y}$.

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>

Interleukin-1α Polymorphism -889C/T Related to Obesity in Korean Taeumin Women

Song, Jeong-Sub,Jeong, Hyun-Ja,Kim, Su-Jin,Son, Mu-Song,Na, Ho-Jeong,Song, Yong-Sun,Hong, Seung-Heon,Kim, Hyung-Min,Um, Jae-Young World Scientific 2008 The American journal of Chinese medicine Vol.36 No.1

<P>Interleukin-1 (IL-1), a cytokine produced predominantly by cells from the macrophage lineage, can affect multiple neuroendocrine and metabolic functions. IL-1α production by cultured peripheral blood mononuclear cells from an obese group was significantly elevated in comparison to a control group. The aim of this study was to investigate whether the IL-1α polymorphism and Sasang constitution, a major branch in Korean traditional medicine, were related to obesity. Genotyping was done in 182 healthy females with a marked variation in body mass index (BMI) by a PCR-restriction fragment length polymorphism assay. The T allele was associated with decreased BMI (p = 0.020). In a subgroup with BMI values ranging from 27 ~ 29 kg/m<SUP>2</SUP>, the frequency of the T allele was significantly decreased (p = 0.004, odds ratio, OR = 0.141 compared to a subgroup with a BMI values less than 25 Kg/m<SUP>2</SUP>). In addition, in Taeumin female subjects, the frequency of the IL-1α T allele was markedly decreased in a subgroup with BMI values in the range of 27 ~ 29 kg/m<SUP>2</SUP>compared to a lean group with BMI values less than 25 kg/m<SUP>2</SUP>(p = 0.004, OR = 0.139). In Korean women, an association was found between -889C/T polymorphism in the regulatory region of the IL-1α gene and BMI values. In addition, an association was found among IL-1α polymorphism, obesity, and the Sasang constitution.</P>

The Korean Association of lnternal Medicine : Poster Session ; PS 1354 : Nephrology ; A Case of Baclofen-Induced Encephalopathy in a Patient with Chronic Kidney Disease

( Song I Lee ),( Byung Hun Lim ),( Jae Hong Lim ),( Duk Eun Jung ),( Jung Sub Song ),( Ju Hung Song ),( Seon Ho Ahn ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Introduction: Baclofen is a gamma-aminobutyric acid(GABA) derivative which is commonly used for hiccup, and spinal origin spasm, pain. baclofen side effects are nausea, vomit, dizziness, weakness, mental state change and respiratory depression. Baclofen is primarily excreted by glomerular fi ltration, so pharmacokinetic of baclofenis signifi cantly affected by kidney disease. In a patient receiving hemodialysis, baclofen toxicity is often reported. However, baclofen toxicity in patients with chronic kidney disease is not reported in korea. This paper reports one case of baclofen toxicity in a patients with chronic kidney disease who does not receiving hemodialysis. Case: A 78 year old patient with chronic kidney disease was admitted due to drowsy mental status after 4days of baclofen treatment in urologic department due to hiccup control. On physical examination, there were no focal neurologic defi cits. Laboratory data showed hyperkalemia and no another abnormality. Brain computed tomography and brain magnetic resonance imaging showed no evidence of acute cerebral hemorrhage or infarction. EEG showed no specifi c abnormality. However correcting serum potassium level, the patient`s mental state didn`t change. After 4days of conservative treatment with baclofen quit, neurologic abnormality was completely recovered. Because the patient maintained normal state of consciousness and no evidence of mental and neurologic abnormality, he was discharged after 12 days of hospitalized day. He is attended hospital outpatients and no abnormality is observed. Conclusions: In conclusion, Physicians should be aware of the possibility of baclofen- induced encephalopathy in old aged patients with chronic kidney disease, and start low dose baclofen in these patients.