• Title/Summary/Keyword: View Factor

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The Fuzzy Steering Control Using a Slope Direction Estimation Method for Small Unmanned Ground Vehicle (경사방향 추정 기법을 이용한 소형로봇의 퍼지 조향 제어)

  • Lee, Sang Hoon;Huh, Jin Wook;Kang, Sincheon;Lee, Myung Chun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.6
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    • pp.721-728
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    • 2012
  • The tracked SUGVs(Small Unmanned Ground Vehicles) are frequently operated in the narrow slope such as stairs and trails. But due to the nature of the tracked vehicle which is steered using friction between the track and the ground and the limited field of view of driving cameras mounted on the lower position, it is not easy for SUGVs to trace narrow slopes. To properly trace inclined narrows, it is very important for SUGVs to keep it's heading direction to the slope. As a matter of factor, no roll value control of a SUGV can makes it's heading being located in the direction of the slope in general terrains. But, the problem is that we cannot directly control roll motion for SUGV. Instead we can control yaw motion. In this paper, a new slope driving method that enables the vehicle trace the narrow slopes with IMU sensor usually mounted in the SUGV is suggested which including an estimation technique of the desired yaw angle corresponding to zero roll angle. In addition, a fuzzy steering controller robust to changes in driving speed and the stair geometry is designed to simulate narrow slope driving with the suggested method. It is shown that the suggested method is quite effective through the simulation.

Post-cure Condition of a Silicone Rubber Material for a LCD Lamp Holder (LCD 램프홀더용 실리콘고무재료의 후가교 조건)

  • Ahn, Won-Sool;Lee, Joon-Man
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.7
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    • pp.1661-1667
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    • 2009
  • Post-cure characteristics of a silicone rubber material which is widely used for a LCD lamp holder were investigated using thermogravimetric analysis (TGA). Research was especially focussed on searching for the optimum post-cure conditions in relation to the practical operation environments. The results showed that incipient volatile temperature(Ti) during the process was considered as the most important factor and, thereby, post-curing for 2hrs at $250^{\circ}C$seemed to be a reasonable condition in the practical view-point. Arrhenius plot of shift factors which were empirically determined from the time-temperature-superposition-principle showed good linearity, exhibiting the post-cure mechanism might be proceeded through single mechanism with activation energy of 108.25kJ/mol.

Restoration of Declined Immune Responses and Hyperlipidemia by Rubus occidenalis in Diet-Induced Obese Mice

  • Lee, Youngjoo;Kim, Jiyeon;An, Jinho;Lee, Sungwon;Lee, Heetae;Kong, Hyunseok;Song, Youngcheon;Choi, Hye Ran;Kwon, Ji-Wung;Shin, Daekeun;Lee, Chong-Kil;Kim, Kyungjae
    • Biomolecules & Therapeutics
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    • v.25 no.2
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    • pp.140-148
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    • 2017
  • Hyperlipidemia, which is closely associated with a fatty diet and aging, is commonly observed in the western and aged society. Therefore, a novel therapeutic approach for this disease is critical, and an immunological view has been suggested as a novel strategy, because hyperlipidemia is closely associated with inflammation and immune dysfunction. In this study, the effects of an aqueous extract of Rubus occidentalis (RO) in obese mice were investigated using immunological indexes. The mice were fed a high-fat diet (HFD) to induce hyperlipidemia, which was confirmed by biochemical analysis and examination of the mouse physiology. Two different doses of RO and rosuvastatin, a cholesterol synthesis inhibitor used as a control, were orally administered. Disturbances in immune cellularity as well as lymphocyte proliferation and cytokine production were significantly normalized by oral administration of RO, which also decreased the elevated serum tumor necrosis factor $(TNF)-{\alpha}$ level and total cholesterol. The specific immune-related actions of RO comprised considerable improvement in cytotoxic T cell killing functions and regulation of antibody production to within the normal range. The immunological evidence confirms the significant cholesterol-lowering effect of RO, suggesting its potential as a novel therapeutic agent for hyperlipidemia and associated immune decline.

Development of Multi-Frequency Impedance Measurement System for Acupuncture Points and Preliminary Report of Measurement Results (Multi-frequency 자극 방식을 이용한 생체 전기 임피던스 측정 시스템 설계 및 경혈의 전기적 특이성에 대한 고찰)

  • Kim, Soo-Byeong;Lee, Na-Ra;Lee, Seung-Wook;Choi, Jun-Young;Lee, Yong-Heum
    • Korean Journal of Acupuncture
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    • v.29 no.1
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    • pp.71-81
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    • 2012
  • Objectives : The purpose of this paper was to suggest new diagnostic method that was to supersede the estimation of electrical properties at acupoints. Thus, we developed the multi- frequencies bioelectrical impedance measurement system so as to analyze the state of bio-ions in body fluid as body compositions, not skin impedance at acupoint. Methods : At low frequency, the current does not penetrate the cell membrane and at high frequency, the current passes through both intracellular and extracellular fluid because of the decreas of cell membrane impedance. To confirm the reflection of composition in extracellular fluid or intracellular fluid of segment such as acupoint, the system was developed to detect the acupoint potential between adjacent two points in the area of LU3, LU4 and LU9 using 5,50 and 200KHz. Results : The detected acupoint potential has been decreased according to elevation of frequency. As a result of correlation of left/right identical acupoint, we observed a high correlation of three types of acupoint potential at multi-frequencies. Moreover, we observed the low correlation at 5KHz, and that was a significant factor to be considered as unbalanced relationship of identical acupoints. Conclusions : On the basis of meridian theoretical point of view, we may infer the acupoint's physiological composition using the multi-frequencies bioelectrical impedance measurement system.

A Simulation of City Viewscape Using Digital Photogrammetry and GIS (수치사진측량 및 GIS에 의한 도시경관 시뮬레이션)

  • 최병길
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.3
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    • pp.323-329
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    • 2002
  • This paper aims at three dimensional simulation and quantitative analysis fer city height planning using digital photogrammetry and GIS. Land view has been neglected while the cities in Korea have been developed rapidly and quantitatively It is, however recognized that Land viewscape is an important factor to achieve a high quality of life. Land viewing is shape and subjective, which makes quantitative and objective analysis of urban viewscape not easy. In this study, a spatial database was constructed by aerial color photographing and digital photogrammetry. The analysis of photographic image were performed using 3-D simulation. Numerical and quantitative analysis for the height planning of building was carried out by producing the vertical profiles of existing buildings and terrain at sight lines. As the result of this study, it was found that the hight planning in a city could be made quantitatively and objectively using 3-D viewscape analysis.

Image Analysis of Korean Automobiles Using Sensory Engineering (감성공학을 이용한 국산 승용차 이미지 분석)

  • Lee Jin-Choon;Hong Seong-Il
    • Journal of Korea Society of Industrial Information Systems
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    • v.11 no.2
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    • pp.69-78
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    • 2006
  • This paper is concerned with analyzing the images of Korean automobiles using, so called, sensory engineering, which adapts the sensory and subjective assessment of human beings in evaluating the quality of product. The methodology of analysis is suggested in this paper according to the following steps. First, 14 pairs of adjectives, which describe the image of object cars in view of the semantic differential method, are derived from consulting with several expert panels. Nextly, factor analysis is performed in order to obtain the axises, by which the images space of the object automobiles are specified, and then the images of the object automobiles are measured by the coordinate of all the object automobiles in the image space. In this paper, a sensory estimation experiment is performed to a panel consisting with In undergraduate students residing in the region of Daegu. From the result of analysis of this paper, target images, which the automobile manufacturers are intended, are achieved by and large except one company.

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Temperature Factor in Silvicultural View Point in Korea - Especially on Warmth- and Cold Index - (조림학적(造林學的)으로 본 온도인자(温度因子) - 온량지수(溫量指數)와 한량지수(寒量指數)를 중심(中心)으로 -)

  • Yim, Kyong-Bin;Lee, Soo-Wook
    • Journal of Korean Society of Forest Science
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    • v.25 no.1
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    • pp.1-12
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    • 1975
  • In this study, warmth and cold-indices were calculated from the climatic records for 30 year from 1931 to 1960 observed at the 80 weather stations as illustrated in Table 1 and Figs. 4 and 5. Iso-warmth index and iso-cold index lines were carefully tracked. However, subjectivity might be involved in this delimitation. The well recognized phenomena of phenology, the natural distribution of specified tree species and potentially cultivable zones of some species of economic importance were discussed with regard to these indices. It is seemed that the forest zones of Korea accepted commonly by foresters and researchers were more rationally matched with the cold indices rather than warmth indices. The forest improvement works by introduction, planting works and other related fields could be refered to these data.

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Spatio-temporal Dynamic Alteration of Forest Canopy Density based on Site Associated Factor: View from Tropical Forest of Nepal

  • Panta, Menaka;Kim, Kye-Hyun
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.313-323
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    • 2006
  • Forest Canopy Density is a dynamic process mediated by various natural and anthropogenic factors. It can be changed over time and locations in the same forest type and landscape. However, human dimensions are considered as the primary force of landscape change and subsequent forest canopy loss in tropical regions of the world. Many studies have been indicated that roads have a far greater impact on forests than simply allowing access for human use. Similarly, rivers have been used as means of transportation, hence illegal logging and felling further deplete forest canopy density. The main objective of this study was to investigate the spatio-temporal dynamic alterations of Forest Canopy Density (FCD) across with site associated factors such as biophysical, physical and human interferences in tropical region of Nepal from 1988 to 2001. Landsat TM and ETM+ of 1988 and 2001 were used to assess the spatial and temporal dynamic alterations of FCD. This analysis revealed that distance to human settlements at P=<0.01, rivers, human interferences (path and fire) and species composition had a statistically significance at P=<0.05 level. However, other factors did not show any significant relation. So, we concluded that understanding of dynamic alterations of FCD with respect to factors was quite complex phenomena. Other surrounding environment could also playa significant role. A comprehensive analysis could be required to understand such complexities. Therefore, additional factors such as climatic, biophysical, social, and institutional with respect to spatio-temporal variability should be considered for the better understanding of canopy dynamic.

PKC Downstream of PI3-Kinase Regulates Peroxynitrite Formation for Nrf2-Mediated GSTA2 Induction

  • Kim, Sang-Geon;Kim, Sun-Ok
    • Archives of Pharmacal Research
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    • v.27 no.7
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    • pp.757-762
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    • 2004
  • The protective adaptive response to electrophiles and reactive oxygen species is mediated by the induction of phase II detoxifying genes including glutathione S-transferases (GSTs). NF-E2-related factor-2 (Nrf2) phosphorylation by protein kinase C (PKC) is a critical event for its nuclear translocation in response to oxidative stress. Previously, we have shown that peroxynitrite plays a role in activation of Nrf2 and Nrf2 binding to the antioxidant response element (ARE) via the pathway of phosphatidylinositol 3-kinase (PI3-kinase) and that nitric oxide synthase in hepatocytes is required for GSTA2 induction. In view of the importance of PKC and Pl3-kinase in Nrf2-mediated GST induction, we investigated the role of these kinases in peroxynitrite formation for GSTA2 induction by oxidative stress and determined the relationship between PKC and PI3-kinase. Although PKC activation by phorbol 12-myristate-13-acetate (PMA) did not increase the extents of constitutive and inducible GSTA2 expression, either PKC depletion by PMA or PKC inhibition by staurosporine significantly inhibited GSTA2 induction by tert-butylhydroquinone (t-SHa) a prooxidant chemical. Therefore, the basal PKC activity is req- uisite for GSTA2 induction. 3-Morpholinosydnonimine (SIN-1), which decomposes and yields peroxynitrite, induced GSTA2, which was not inhibited by PKC depletion, but slightly enhanced by PKC activation, suggesting that PKC promotes peroxynitrite formation for Nrf2-mediated GSTA2 induction. Treatment of cells with S-nitroso-N-acetyl-penicillamine (SNAP), an exogenous NO donor, in combination with t-BHQ may produce peroxynitrite. GSTA2 induction by SNAP + t-BHQ was not decreased by PKC depletion, but rather enhanced by PKC activation, showing that the activity of PKC might be required for peroxynitrite formation. LY294002 a P13-kinase inhibitor blocked GSTA2 induction by t-BHQ, which was reversed by PMA-induced PKC activation. These results provide evidence that PKC may playa role in formation of peroxynitrite that activates Nrf2 for GSTA2 induction and that PKC may serve an activator for GSTA2 induction downstream of PI3-kinase.

Key-factors in the Modified Parallel Type to Convert Toed-in Type Stereoscopy (수렴타입의 스테레오 영상 획득방법을 모사하는 변형평행타입에서의 주요인자의 정의)

  • Lee, Kwang-Hoon;Kim, Dong-Wook;Kim, Sung-Kyu
    • Korean Journal of Optics and Photonics
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    • v.19 no.4
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    • pp.276-286
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    • 2008
  • The representative alignments for taking a stereo image by using a stereoscopic camera are the toed-in and the parallel alignment. In this paper, we tried to find important factors in the process that captures the stereo image by modifying parallel type 3D camera alignment to take the same object information as, for instance, when toed-in type was used. The modified parallel type 3D camera has merits in both types. As a result, three important factors are found by simulation to be inter-camera distance, field of view and convergence angle for both types. And the change of the convergence angle is known to be the most important factor at the stereo fusible area in processing. The effective ranges of these factors to simulate perfectly toed-in type by modified parallel type are strongly dependent on a user's circumstances such as mobile, official, theater and so on. Additionally, the error of the simulation is reduced when the focal length of the stereo camera is short and the convergence angle becomes smaller.