EFFECT OF TORSION ON FLOWS IN SPIRAL TUBES WITH SQUARE CROSS-SECTION

Nahm Keon Hur,Seong Young Yoon,Kwang Ho Kim 대한기계학회 1992 International Conference on Fluid Machinery Vol.1 No.1

Eigenfunction fluctuations and correlations at the mobility edge in a two-dimensional system with spin-orbit scattering

NAHM, IN-HYUN 성화대학교 1993 成和論叢 Vol.- No.1

The critical behaviour of wavefunctions at the Anderson metal-insulator transition is studied by numerical simulation, using as an example of a system with a mobility edge, a two-dimensional tight-binding model with spin-orbit scattering. It is demonstrated that individual eigenstates have multifractal fluctuations of their probability density. The influence of these fluctuations on two-particle correlations is examined via calculations of the wavevector and frequency dependence of the diffusion constant.

IgA and IgG Antibodies to Streptococcus Pneumoniae in Induced Sputum from Asthmatic Patients

Nahm, Dong-Ho,Park, Hae-Sim 아주대학교 1997 아주의학 Vol.2 No.1

Eosinophils are known to be main effector cells in airway inflammation of bronchial asthma and contribute to epithelial damage by degranulation of cytotoxic granular proteins. The mechanism of eosinophil degranulation in asthmatic airway is still poorly understood. There have been some in vitro data suggesting immunoglobulins as a stimulus for eosinophil degranulation. In order to evaluate a possible role of specific antibodies to bacterial organism on eosinophil degranulation within airway secretion from atopic asthmatic patients, we measured IgA and IgG antibodies to Streptococcus pneumoniae polysaccharide antigen in the induced sputum from 16 atopic asthmatic patients and 12 non-atopic non-asthmatic controls by enzyme-linked immunosorbent assay (ELISA). Eosinophil cationic protein (ECP) levels were measured in induced sputum from 16 atopic asthmatic patients. Levels of specific igA antibodies to S. pneumoniae in the induced sputum from mite-sensitive asthmatic patients were significantly higher than those from controls (p< 0.005). No significant difference was found in the levels of IgG antibodies to S. pneumoniae in induced sputum between asthmatics and controls. ECP levels in induced sputum from mite-sensitive asthmatics correlated significantly with the levels of specific igA antibodies to S. pneumoniae (r=0.56, p< 0.05), but not with lgG antibodies to S. pneumoniae. These results suggest that IgA antibodies to bacterial antigen could participate in eosinophil degranulation in the airway secretion from atopic asthmatics patients.

From Seoul Metropolitan Region to Networked Seoul Area? : Locational Dynamics and Specialization in the Seoul Metropolitan Area

Nahm, Kee-Bom 誠信女子大學校 韓國地理硏究所 1997 應用地理 Vol.- No.20

Urban region evolves as the horizontal relations (the general and tendentiously global spatial relations) and vertical relations (the characteristics of local environment) are interwoven in the worldwide establishments of the modern economy and society. This evolution creates modern urban networks, a system of cities interconnected by a grid of well-defined local and global relations, as the uncertainty of the world economy increases and regional industrial mileu rapidly changes, Christallian urban structures based on hierarchical nesting of relations, which link cities together, are transformed into networked urban structures based on information-telecommunications technology infrastructures and increasing flexibilities and complementarity among virtual agglomeration of cities. This study investigates the transformation of Seoul Metropolitan region from monocentric Christallian central place to multicentric urban agglomeration network area. Analyzing population data including migration, commuting, and travels and the changes in industrial structure and transportation networks, the study concludes that Seoul Metropolitan region is moving forward to a newer 'network-based urban agglomeration' and suggests that policy practitioners should aware of supplying proper informational and managerial infrastructure arrangements to keep the development pace. Lastly, the paper addresses further research avenues for the development of network city with reference to the two frontier cities like Randstad, The Netherlands and Kansai region, Japan.

An Extension to an Open Economy of Lucas's Growth Model : Optimum Growth Rate Case 최적 성장율 비교

Nahm, Pyeong-Tak 경일대학교 산업정보연구소 1994 産經硏究 Vol.5 No.1

Romer(1986)가 내생적 경제성장모델을 제시한이래 Lucas(1988)가 인간자본의 외부효과를 고려한 내생적모델을 제시함으로써 이 분야에 큰 기여를 하였다. 본고에서는 Lucas(1988)의 경제발전모델을 소규모 개방경제로 확장해보았다. 무역수지균형이 요구되지 않는 경우의 개방경제하에서의 최적성장율을 도출하여 Lucas의 폐쇄경제의 경우와 비교하였다. 그 결과 만약 국내자본 및 수입자본의 분배몫의 합이 개방전의 자본의 분배몫보다 증가한다면, 이 경제는 개방함으로써 더높은 최적성장율을 달성할 수 있다는 것을 보여준다.

Impulse Degradation Behavior of ZPCCYE Varistors with Y₂O₃/Er₂O₃ Ratio

Nahm, Choon-Woo,Park, Jong-Hyuk The Korean Institute of Electrical and Electronic 2011 Transactions on Electrical and Electronic Material Vol.12 No.5

The nonlinear electrical properties and degradation behavior against an impulse-current of 400 A in the ZnO-$Pr_6O_{11}$-CoO-$Cr_2O_3$-$Y_2O_3$-$Er_2O_3$ (ZPCCYE) varistors were investigated with different $Y_2O_3/Er_2O_3$ ratios. The $Y_2O_3/Er_2O_3$ mole ratio has a significant effect on nonlinear electrical properties and impulse degradation behavior of the ZPCCYE varistors. The varistors added with $Y_2O_3/Er_2O_3$ = 0.5/0.5 exhibited the best nonlinear properties with 39 in nonlinear coefficient (${\alpha}$) and the best clamp characteristics, in which the clamping voltage ratio (K) was in the range of K = 1.62-2.18 at an impulse-current of 1-50 A. The varistors added with $Y_2O_3/Er_2O_3$ = 0.25/0.5 exhibited the best electrical stability, with $%{\Delta}E_{1mA/cm^2}$=-5.6%, $%{\Delta}{\alpha}$ = 6.7%, and $%{\Delta}J_L$ = -14.6% against an impulse-current of 400 A. On the contrary, the varistors added with $Y_2O_3/Er_2O_3$ = 0.5/0.5 were destroyed applying an impulse-current of 400 A.

Magnetic and structural properties of ultrathin magnetic films: Ni/Pt(111)

Nahm, T.U.,Oh, S.J. The Korean Vacuum Society 2003 Applied Science and Convergence Technology Vol.12 No.1

We have studied magnetic and structural properties of ultrathin Ni films grown on PI(lII) surface using in situ surface magneto-optic Kerr effect and X-ray photoelectron spectroscopy. Perpendicular magnetic anisotropy was absent, and longitudinal Kerr signal was only detectable for Ni films thicker than 6 monolayers. Enhancement in longitudinal Kerr signal by 30% was achieved by post-annealing at temperatures below 800K, but upon annealing at 820K, surface alloy was formed. By using core-level binding-energy shifts, the composition was determined to be Ni 70 at. %.

The Syntactic Component in a Transformational Grammar

Nahm Sheik Park(朴南植) 서울대학교 언어교육원 1969 語學硏究 Vol.5 No.1

Holocene Paleosols of the Upo Wetland, Korea

Nahm, Wook-Hyun,Kim, Ju-Yong,Yang, Dong-Yoon,Hong, Sei-Sun,Lee, Jin-Young,Kim, Jin-Kwan Korea Association For Quaternary Research 2003 제사기학회지 Vol.17 No.2

The Upo wetland, the largest natural wetland in Korea, is located in Changnyeong-gun, Gyeongsannam Province ($35^{\circ}33'$ N, $128^{\circ}25'$ E), and 70 km upstream from the Nakdong River estuary. Unlike most other Korean wetlands that have been destroyed under the name of economic development, the Upo wetland has been able to preserve its precious ecosystem throughout the years. Thanks to increased public awareness about natural wetlands and environmental conservation, the Korean Ministry of Environment designated the Upo wetland an 'Ecological Conservation Area' on July 26th, 1997. On March 2nd of the following year, the Upo wetland (8.54 $\textrm{km}^2$) was designated a 'Protected Wetland' in accordance with the international Ramsar Treaty. A 4.49m long (from 9.73 to 5.24 m in altitude) UP-1 core ($35^{\circ}33'05"N$, $128^{\circ}25'17"E$), recovered in the marginal part of the Upo wetland, is divided into eight buried paleosol units of different ages on the basis of the abundance of color mottles and vertical color variations (Aslan et al., 1998). Radiocarbon datings suggested that the paleosol profile represent the last 5700 years. The entire section of the core was more or less subjected to pedogenetic processes, and shows very weak to moderate soil profile development. These Holocene paleosols are therefore regarded as synsedimentary soils of deluvium (deposits formed by floods) origin (Sycheva et al., 2003). Unit 1 to 5 paleosols are generally silt-rich and exhibit moderate profile development. The boundaries between the units are somewhat distinguishable, but not so clear cut. This is due to variable repeated combination of accumulation, denudation and soil forming processes within various periods. Mottle textures gradually decrease in abundance with increasing clay content in Unit 6, which results in weak profile development. The lower boundary of Unit 6 lies around about 2000 yrBP, the beginning of Subatlantic in Korea (Kim et al., 2001). Abrupt sediment textural change is detected in Unit 7, which is interpreted to indicate the human activities on the Upo wetland. Unit 8 represents the recent soil forming processes. The preliminary results of this ongoing study imply the primary factor for pedogenetic processes is the water table fluctuations related to the sedimentary textures like grain size distributions, and the geomorphological stability of the Upo wetland.o wetland.

Autologous Immunoglobulin Therapy in Patients With Severe Recalcitrant Atopic Dermatitis: A Preliminary Report

Nahm, Dong-Ho,Cho, Su-Mi,Kim, Myoung-Eun,Kim, Yeo-Jin,Jeon, Sook-Yeong The Korean Academy of Asthma, Allergy and Clinical 2014 Allergy, Asthma & Immunology Research Vol.6 No.1

<P>The management of severe recalcitrant atopic dermatitis (AD) is a challenging issue for clinicians and patients. We hypothesized that repeated intramuscular injections of autologous immunoglobulin (autologous immunoglobulin therapy: AIGT) might induce clinical improvements in patients with AD by stimulation of the active immune response to antigen-binding-site of pathogenic antibodies. We tried AIGT in 3 adult patients with severe recalcitrant AD whose clinical conditions could not be effectively controlled by medical treatments (including oral cyclosporine) for more than 2 years. Autologous immunoglobulin was purified from the autologous plasma by affinity chromatography using Protein A. The patients were treated by an intramuscular injection of 50 mg of autologous immunoglobulin twice a week for 4 weeks. A clinical severity score of AD (SCORAD value) showed a decrease greater than 30% at 8 weeks after the initiation of AIGT compared with the baseline before the initiation of AIGT in all 3 patients with severe recalcitrant AD. No significant side effects from treatment were observed. Further studies with larger numbers of patients are required to evaluate the clinical usefulness of AIGT for AD.</P>