• Title/Summary/Keyword: gap line

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Temperature Fluctuations Over the Past 2000 Years in Western Mongolia

  • Pederson, Neil;Jacoby, Gordon C.;D′Arrigo, Rosanne.;Frank, David;Buckley, Brendan;Nachin, Baatarbileg;Chultem, Dugarjav;Renchin, Mijiddorj
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.157-159
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    • 2003
  • Much of northern Asia is lacking in high-resolution palaeoclimatic data coverage. This vast region thus represents a sizeable gap in data sets used to reconstruct hemispheric-scale temperature trends for the past millennium. To improve coverage, we present a regional-scale composite of four tree-ring width records of Siberian pine and Siberian larch from temperature-sensitive alpine timber-line sites in Mongolia. The chronologies load closely in principal components analysis (PCA) with the first eigenvector accounting for over 53% of the variance from ad 1450 to 1998. The 20-year interval from 1974 to 1993 is the highest such growth period in this composite record, and 17 of the 20 highest growth years have occurred since 1946. Thus these trees, unlike those recently described at some northern sites, do not appear to have lost their temperature sensitivity, and suggest that recent decades have been some of the warmest in the past 500 years for this region. There are, however, comparable periods of inferred, local warmth for individual sites, e.g., in 1520-1580 and 1760-1790. The percent common variance between chronologies has increased through time and is highest (66.1%) in the present century. Although there are obvious differences among the individual chronologies, this result suggests a coherent signal which we consider to be related to temperature. The PCA scores show trends which strongly resemble those seen in recent temperature reconstructions for the Northern Hemisphere, very few of which included representation from Eurasia east of the Ural Mountains. The Mongolia series therefore provides independent corroboration for these reconstructions and their indications of unusual wanning during the twentieth century.

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AUTOMATIC MULTITORCH WELDING SYSTEM WITH HIGH SPEED

  • Moon, H.S;Kim, J.S.;Jung, M.Y.;Kweon, H.J.;Kim, H.S.;Youn, J.G.
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.320-323
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    • 2002
  • This paper presents a new generation of system for pressure vessel and shipbuilding. Typical pressure vessel and ship building weld joint preparations are either traditional V, butt, fillet grooves or have narrow or semi narrow gap profiles. The fillet and U groove are prevalently used in heavy industries and shipbuilding to melt and join the parts. Since the wall thickness can be up to 6" or greater, welds must be made in many layers, each layer containing several passes. However, the welding time for the conventional processes such as SAW(Submerged Arc Welding) and FCAW(Flux Cored Arc Welding) can be many hours. Although SAW and FCAW are normally a mechanized process, pressure vessel and ship structures welding up to now have usually been controlled by a full time operator. The operator has typically been responsible for positioning each individual weld run, for setting weld process parameters, for maintaining flux and wire levels, for removing slag and so on. The aim of the system is to develop a high speed welding system with multitorch for increasing the production speed on the line and to remove the need for the operator so that the system can run automatically for the complete multi-torch multi-layer weld. To achieve this, a laser vision sensor, a rotating torch and an image processing algorithm have been made. Also, the multitorch welding system can be applicable for the fine grained steel because of the high welding speed and lower heat input compare to a conventional welding process.

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An adaptive fuzzy control for closed-die ring-rolling process ("Ring 생산 Control System의 퍼지 적응제어")

  • 이용현
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1476-1479
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    • 1996
  • The ring rolling process is one of the best known ring production method. The present model based control system was designed for rings with rectangle cross-section yet. An Adaptive Fuzzy Control for Closed-Die Ring-Rolling was developed in order to enhance the flexibility of the radial-axial ring rolling machine and to produce the rings with highly complex cross-section profile, roller bearing rings. A fuzzy method was implemented because of its simple application and to utilize the known process knowledge. The quality of the control system was estimated by die filling grad, which is strong dependent on the rising time of the controller. The rolling process parameters were also varied to determine their influence on filling of the ring profile. Die filling met the requirement of the industry.

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MARGINAL FIDELITY AND FRACTURE STRENGTH OF IN-CERAM CROWNS ACCORDING TO VARIOUS RESIN CEMENTS (접착재의 종류에 따른 In-Ceram 도재관의 변연적합도와 파절강도에 관한 연구)

  • Lim, Ju-Hwan
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.6
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    • pp.888-899
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    • 1998
  • In-Ceram system is one of contemporary esthetic all ceramic restorations and has relatively high flexural strength. The purpose of this study was to evaluate the marginal fidelity according to type of resin cement and measuring position, and to evaluate fracture strength according to type of resin cement. In this study, twenty seven In-Ceram crowns were fabricated on the metal master die of prepared maxillary right central incisor and devided into three groups. All specimens were cemented with Panavia 21 (group PV), Super-bond (group SB) and Lute-it (group LI) on the metal master die. After cementation, specimens were measured marginal gap between the margin of the In-Ceram crown and the finishing line of metal master die by using a stereomicroscope (SZ-ST, Olympus, Japan). Marginal gaps were recorded at the labial, lingual, mesial and distal measuring points on the metal master die. For the mesurement of fracture strength, lingual surfaces of cemented specimens were loaded at a distance of 1mm from incisal edge by using the Autograph S-2000 (Shimadzu, Japan). The results of marginal fidelity and fracture strength were statistically analyzed with the SPSS version 8.0 programs. The results of this study were as follows: 1. In comparison of marginal fidelity according to the measuring points, there was no significant difference. 2. The marginal fidelity according to the type of resin cement was decreased in order of group $LI\;(63.75{\mu}m),\;SB\;(77.78{\mu}m),\;PV\;(86.53{\mu}m)$, and there was significant difference between group LI and PV (p<0.05). 3. The fracture strength according to the type of resin cement was showed descending order of group $LI\;(60.00kg/cm^2),\;SB\;(56.80kg/cm^2),\;PV\;(56.11kg/m^2)$, but there was no significant difference.

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Disparity in opinions on lip protrusiveness in contemporary African American faces

  • Battle, Yvette;Schneider, Monica;Magder, Laurence;Pae, Eung-Kwon
    • The korean journal of orthodontics
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    • v.48 no.1
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    • pp.23-29
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    • 2018
  • Objective: In accordance with the changing demographics in the United States, orthodontists working on various ethnic populations should be more conscious when using the standardized profile analyses for the African American patient. The objective of this study was to examine whether the perception of lip protrusiveness in modern African American faces has changed. For this purpose, we investigated the most favorable African American lip profile using the opinions of 10 experienced and 10 newly trained younger orthodontists. Methods: Attractiveness was converted to a number on visualized analog scales. Comparative ranks on 16 African American profiles, with focus on lip protrusiveness and thickness, were made among the groups. Mixed-effects linear regression models were fit and group differences were estimated. Results: Younger orthodontists favored a more protrusive lip profile, and the variance in their perceptions was narrower than those of older orthodontists. Measurements related to upper lip protrusion showed the strongest correlation to attractiveness (r = -0.82). The association with attractiveness decreased linearly as the protrusiveness of the upper lip increased. Steiner's E-line was the most influential reference for determining the level of attractiveness for the older orthodontists, whereas upper lip protrusion was the most influential factor for the young orthodontists. Conclusions: An adequate level of lip protrusiveness and thickness should be essential for maintaining attractive esthetics in African American patients. Yet, a new set of standards for prominent lips in this population is necessary to reflect the current trend in the concept of a beautiful face in the modern world.

Spectrum Measurement Study of Arc Plasma on Triggered Vacuum Switch (TVS) (TVS에서 아크 플라즈마의 분광 측정 연구)

  • Nam, S.H.;Han, Y.J.;Lee, B.J.;Kim, S.H.;Park, S.S.
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1732-1734
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    • 2001
  • The purpose of this experiment was to develope Triggered Vacuum Switch(TVS) and to improve understanding of the high current vacuum arc phenomena in the TVS. The TVS has an array of rods of alternate polarity in which a fixed gap spacing is maintained between the rods. The cross section of each rod has trapezoidal shape. Breakdown of the TVS produced high current vacuum arc plasma. A spectroscopic measurement was performed over 20 kA peak current in the center of electrodes, in the vicinity of cathode, and outside electrodes. The electrode material tested was Fe. Measured Fe spectrum range was from 200 nm to 900 nm. Measurement result showed that over 90 percent of the charge states were FeII and the others were FeI and FeIII. The electron temperature was determined from the relative line intensity ratio methode of FeII system by assuming the local thermal equilibrium(LTE). The electron temperature at the center of electrodes was measured as 1.5 eV at 26 kA peak current. The electron temperature varied with its peak current. Intensity of spectrums is the highest in the vicinity of the cathode. Further we will also present study result of the diode phenomena in the TVS.

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Groundwater Balance in Urban Area (도시지역의 지하수수지)

  • Lee, Seung-Hyun;Bae, Sang-Keun
    • Journal of Environmental Science International
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    • v.20 no.12
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    • pp.1553-1560
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    • 2011
  • The study analyzes groundwater balance with regard to the water recharge and discharge which contain urbanization components in Suyeong-gu, Busan. It also verifies the reliability and accuracy improvement on the analysis of the balance. The result of the study is viewed as preliminary data which are useful to develop, utilize and manage groundwater. The average quantity of groundwater recharge is 6,014.1 $m^3$/day in the research area during the last ten year period(from 1998 to 2007). The outflow from drainage areas to rivers and coasts is 149.3 $m^3$/day, the inflow from rivers and coasts to drainage area is 439.9 $m^3$/day. The use of the water is 4,243.0 $m^3$/day. The outflow caused by subway in line No.2 and No.3 through Suyeong-gu and the one by building an underground electric complex is 1,500.0 $m^3$/day. The leakage of water works is 6514.9 $m^3$/day. The inflow and outflow of sewerage is 5082.2 $m^3$/day from groundwater to sewer. The amount of groundwater recharge, the inflow from rivers and coasts to drainage area, and the leakage of water works belong to the amount of groundwater inflow and the total amount is 12,968.9 $m^3$/day. The amount of outflow from drainage area to rivers and coasts, the use of groundwater, outflow by subway and underground electric complex tunnel and the amount of inflow of the water to sewerage belong to the amount of outflow of groundwater and the sum amount is 13,031.5 $m^3$/day. The gap between the amount of inflow and outflow of groundwater is 62.6 $m^3$/day, which is considered to reflect the trend that the short term drop in the amount of rainfall results in the amount of groundwater recharge and that the amount of outflow from drainage area to rivers and coasts decreases.

CRLH Rectangular Waveguide with Balanced Condition above Cut-off Frequency (차단 주파수 이상에서 평형 조건을 만족하는 CRLH 직각 도파관)

  • Kim, Dong-Jin;Lee, Jeong-Hae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.9
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    • pp.912-918
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    • 2011
  • In this paper, a composite right-/left-handed(CRLH) rectangular waveguide satisfying a balanced condition above the cut-off frequency is presented. The proposed structure consists of one shorted stub and two twisted H-plane irises which produce an effectively negative permeability and permittivity, respectively. The CRLH structure can independently control the series and shunt resonance frequencies of a CRLH transmission line which determine the left-handed(LH) and right-handed(RH) bands due to a minimized coupling between a shorted stub and twisted H-plane irises. Thus, the design of the CRLH waveguide satisfying a balanced condition is possible. To analyze the CRLH structure, a crossly connected equivalent circuit is derived. The simulated and measured results confirm that the proposed CRLH waveguide has a transmission property without a band gap among the LH and RH bands.

Connexin32 inhibits gastric carcinogenesis through cell cycle arrest and altered expression of p21Cip1 and p27Kip1

  • Jee, Hyang;Lee, Su-Hyung;Park, Jun-Won;Lee, Bo-Ram;Nam, Ki-Taek;Kim, Dae-Yong
    • BMB Reports
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    • v.46 no.1
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    • pp.25-30
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    • 2013
  • Gap junctions and their structural proteins, connexins (Cxs), have been implicated in carcinogenesis. To explore the involvement of Cx32 in gastric carcinogenesis, immunochemical analysis of Cx32 and proliferation marker Ki67 using tissue-microarrayed human gastric cancer and normal tissues was performed. In addition, after Cx32 overexpression in the human gastric cancer cell line AGS, cell proliferation, cell cycle analyses, and $p21^{Cip1}$ and $p27^{Kip1}$ expression levels were examined by bromodeoxyuridine assay, flow cytometry, real-time RT-PCR, and western blotting. Immunohistochemical study noted a strong inverse correlation between Cx32 and Ki67 expression pattern as well as their location. In vitro, overexpression of Cx32 in AGS cells inhibited cell proliferation significantly. $G^1$ arrest, up-regulation of cell cycle-regulatory proteins $p21^{Cip1}$ and $p27^{Kip1}$ was also found at both mRNA and protein levels. Taken together, Cx32 plays some roles in gastric cancer development by inhibiting gastric cancer cell proliferation through cell cycle arrest and cell cycle regulatory proteins.

Deformation Characteristics of Construction Joint of Paved Track on Earthwork Section using the Accelerated Track Test (궤도가속실험을 통한 포장궤도 토공구간 시공이음매부의 변형특성 연구)

  • Lee, Il-Wha;Jang, Seung-Yup;Kang, Yoon-Suk;Um, Ju-Hwan;Kim, Eun
    • Journal of the Korean Society for Railway
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    • v.13 no.5
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    • pp.521-527
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    • 2010
  • The Paved Track is applied to reduce maintenance cost of conventional line. The Paved Track could be used in all types of lines including earthwork, bridge, tunnel and turnout sections. In case of earthwork section, the construction joint is the most critical factor to track durability. The construction joint does not affect to the track structure directly, but the gap due to discontinuity of slabs may affect to the long-term serviceability. To evaluate this problem, the accelerated track test has been performed on the construction joint and the middle part to of the real scale Paved Track. The purpose of this test is that evaluate the vulnerability of construction joint section comparing the trends of settlement and earth pressure under repeated loads of construction joint with those of the middle slab part.