• Title/Summary/Keyword: surface changes

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Changest in Electric Potentials of Leaf Surface Induced by Environmental Stimuli (환경자극에 따른 식물의 엽표면 전위포텐셜의 변화)

  • 손기철;류명화;길미정
    • Journal of Bio-Environment Control
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    • v.9 no.2
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    • pp.94-100
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    • 2000
  • This study was conducted to investigate the changes of electric potentials of leaf surface induced by environmental stimuli in plant. The values of electric potentials varied with different intervals of light on and off, and light qualities and moreover, their changes were also varied according to the time of a day. Additionally, stimuli such as candle light, wind, or 5$^{\circ}C$ cool water spray also evoked considerable changes in leaf surface electric potentials and their signal patterns varied with species of plants tested. In frequency analysis of electric potentials, the distribution values by FFT were highest in 1-10 Hz frequency zone by the majority of stimuli. These results suggested that changes in leaf surface electric potentials depended upon plant species even though stimulus was the same and vice versa.

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Application of On-line System for Monitoring and Forecasting Surface Changes for Korean Peninsula

  • Lee, Sang-Hoon
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.268-273
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    • 1998
  • This study applies an on-line system, which employes an adaptive reconstruction technique to monitor and forecast ocean surface changes. The system adaptively generates an appropriate synthetic time series with recovering missing measurements for sequential images. The reconstruction method incorporates temporal variation according to physical properties of targets and anisotropic spatial optical properties into image processing techniques. This adaptive approach allows successive refinement of the structure of objects that are barely detectable in the observed series. The system sequentially collects the estimated results from the adaptive reconstruction and then statistically analyzes them to monitor and forecast the change in surface characteristics.

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RADIOGRAPHIC STUDY OF BONE CHANGES ON TMJ ARTHROSIS (악관절증에서의 골변화양상에 관한 방사선학적 연구)

  • You Dong Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.12 no.1
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    • pp.69-80
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    • 1982
  • The author analyzed the morphologic changes of bone structures from 1256 radiographs of 314 patients with temporomandi.bular joint arthrosis, which were obtained by the oblique-lateral projection and orthopantomography. The interrelations of the bone changes and clinical symptoms were examined. Also, the positional relationships of condylar head, articular fossa and articular eminence in the mouth open and closed state were observed in the patients with bone changes. The results were as follows; 1. The most frequent bone change in the TMJ arthorsis was eburnation of cortical bone (35. 64%) of total cases). Then came bone surface erosion and localized radiolucency (26.18%), marginal proliferation (9.7%) and flattening of articular surface (9.58%) in that order. 2. The most frequent site of bone change was articular eminence (41.70%). The came condylar head (21.09%) and articular fossa (20.73%) in that order. 3. In the patients with bone changes, their clinical symptoms were pain (51.55%), clicking sound during mandibular movement (37.71%) and limited mandibular movement (10.73%). In the patients complaining pain, their radiographs showed eburnation of cortical bone (30.68%), bone surface erosion and localized radiolucency (27.45%) and flattening in the (30.68%), bone surface erosion and localized radiolucency (27.45%) and flattening of articular surface (10.68%). 4. The condylar positional changes in the TMJ arthrosis patients with bone changes were as follows: in the mouth closed !tate, there were the widening of joint space in 624 cases (50.00%), the narrowing of joint space in 543 cases (43.47%) and bone on bone relatioships in 82 cases (6.57%). In the mouth open state, there were forward positioning of the condyle in 332 cases (28.55%), limitation of movenent in 332 cases (28.55%), bone on bone relation- ships in 248 cases (21.31%) and downward positioning of condyle in 217 cases (18.66%). bone on bone relationships in 243 cases (21.32%) and downward positioning of condyle in 217 cases (18.66%). 5. In the TMJ arthrosis patients with bone changes, 1249 cases of abnormal condylar position in the mouth closed state and 1163 cases of abnormal condylar position in the mouth open state could be interpreted. so, for the radiographic interpretation of TMJ arthrosis, the reading of condylar positional changes as well as that of bond changes should be performed and their interrelations should be profoundly considered.

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The Correlation Between Changes of Ankle Joint Position Sense and Sway Area Through Unstable Surface Training (불안정지지면 훈련을 통한 발목관절위치감각 변화와 동요면적 변화간의 상관관계)

  • Ha, Na-Ra;Kim, Myung-Chul;Han, Seul-Ki
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.9
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    • pp.1383-1389
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    • 2013
  • This research was conducted to see the correlation between changes of ankle Joint Position Sense and Sway Area through Unstable Surface training. For the study, 48 healthy males and females were randomly divided into an unstable surface group(n=24) and a stable surface group(n=24). Then, they were asked to carry out the same exercise program three times a week for six weeks. The unstable surface group and stable surface group performed the exercise program on the balance exercise pad and on the hard ground, respectively. As a result, the unstable surface group displayed significantly reduced error of ankle joint position sense and sway area(p<.05). Moreover, a significant correlation between variances of ankle joint position sense and sway area was only found in the unstable surface group. In conclusion, this study demonstrated that there was a significant correlation between changes of ankle joint position sense and sway area through proprioceptive sense training on the unstable surface.

Surface Modification of PET Irradiated by Ultra-Violet (Part I) -Transformation of Chemical Structure and Surface Properties- (UV조사를 통한 PET의 표면개질 (제1보) -화학구조 변화 및 표면특성 변화-)

  • Choi Hae Young;Lee Jung Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.3_4 s.141
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    • pp.561-568
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    • 2005
  • The irradiation of Ultra-Violet (UV) is an efficient treatment for polymer to improve hydrophilic properties. 4-Channel PET knit fabrics were treated with UVA and UVC to develop functional and environment-friendly fabric. The fabric was treated with various treatment times and distances from UV lamps having different wavelength. FT-IR and XPS investigated the chemical changes. To confirm the change of surface properties, contact angle, surface energy and SEM were examined. The study of UV as a treatment for PET knit fabric shows significant changes in chemical and surface properties, which is proved by analyses. FT-IR and XPS analyses prove the augmentation of carboxylic, Hydrophilic groups on the surfaces treated by UV. The increase of water contact angle and surface energy means more water wettable and surface energy of PET film was substantially increased by UV irradiation time. The ageing after surface treatment had little influence on the surface energy of the irradiated PET film. SEM proves the surface modification of PET such as etching, bubble and crack. The negative effects are increased in accordance with increasing treatment time.

The effect of repeated firings on the color change of dental ceramics using different glazing methods

  • Yilmaz, Kerem;Gonuldas, Fehmi;Ozturk, Caner
    • The Journal of Advanced Prosthodontics
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    • v.6 no.6
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    • pp.427-433
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    • 2014
  • PURPOSE. Surface color is one of the main criteria to obtain an ideal esthetic. Many factors such as the type of the material, surface specifications, number of firings, firing temperature and thickness of the porcelain are all important to provide an unchanged surface color in dental ceramics. The aim of this study was to evaluate the color changes in dental ceramics according to the material type and glazing methods, during the multiple firings. MATERIALS AND METHODS. Three different types of dental ceramics (IPS Classical metal ceramic, Empress Esthetic and Empress 2 ceramics) were used in the study. Porcelains were evaluated under five main groups according to glaze and natural glaze methods. Color changes (${\Delta}E$) and changes in color parameters (${\Delta}L$, ${\Delta}a$, ${\Delta}b$) were determined using colorimeter during the control, the first, third, fifth, and seventh firings. The statistical analysis of the results was performed using ANOVA and Tukey test. RESULTS. The color changes which occurred upon material-method-firing interaction were statistically significant (P<.05). ${\Delta}E$, ${\Delta}L$, ${\Delta}a$ and ${\Delta}b$ values also demonstrated a negative trend. The MC-G group was less affected in terms of color changes compared to other groups. In all-ceramic specimens, the surface color was significantly affected by multiple firings. CONCLUSION. Firing detrimentally affected the structure of the porcelain surface and hence caused fading of the color and prominence of yellow and red characters. Compressible all-ceramics were remarkably affected by repeated firings due to their crystalline structure.

A Study on Analysis of Breast Shapes by Replica Experiments (Replica법을 이용한 성인 여성 유방 형태 분석에 관한 연구)

  • 이경화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.4
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    • pp.689-698
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    • 1997
  • The purpose of this study is to develop the well-fitted brassieres by observing the changes in the breast sizes and shapes, the surface area and the volume of the breast through the arm movements of 3 types (0$^{\circ}$, 90$^{\circ}$ and 180$^{\circ}$) in vertical motion. The subjects are females, who are aged twenties and wearing a brassiere size 70B, In particular, to obtain the measures regarding the surface area and the volume of the breast, replicas are made at each motion. The results of this study are as follows: 1. The changes in the breast sizes and shapes at each motion By increasing the motions of the arm movement, the following measure items are inclined to decrease: Shoulder length, Side neck point~B.P., Front neck point~B.P., Horizontal length of the cup, Upper bust circumference, Bust circumference, Upper bust depth, Bust depth, Under bust depth, Nipple to tipple breadth, Horizontal distance of bust, Bust height, Cup size. By increasing the motions of the arm movement, the following measure items are inclined to increase: Center point of shoulder~B.P., Shoulder point~B.P., Armpit~ lowest point of breast drooping, Upper bust point~B.P., B.P~Under bust point, Under bust line, Width of gap between breast, Vertical distance of Bust. 2. The changes in the surface area and volume of breast at each motion By making the replica to observe changes in the surface area, which are sectioned to 4 parts(area 1 to area 4) , and volume of breast at each motion, the results are as follows: At 0$^{\circ}$ and 90$^{\circ}$, the sizes of each part are ordered as the following: area2> areal> area4> area3. At 180$^{\circ}$, the sizes of each part are ordered as the following: areal> area2> area4> area3. Through these orders, it is found that the upper and inside part of the breast has the inclination to increase so long as the motions of the arm movement increase. Also, the total surface area increases so long as the motions of the arm movement increase. The volume of the breast increase when the surface area of the breast increases. As a result of the F-test on the changes in the each surface areas, the surface area and volume by arm movements, the significant differences among the each surface areas and the surface area are not found.

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Surface Quality Improvements on the Spherical Shaped Mold using Ball End Milling (볼 엔드밀을 이용한 금형 구면 가공의 표면품질 향상에 관한 연구)

  • Yun, Il-Woo;Hwang, Jong-Dae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.3
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    • pp.71-76
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    • 2020
  • Various machining methods are being studied to improve the processing quality of the spherical R shape in press die. In this paper, we confirmed that changes in machining quality were associated with changes in cutting direction, path, and cutting angle, which are commonly used in the machining of molds. We obtained a surface roughness graph with each condition change in one specimen using an instrument that measured geometry and surface roughness simultaneously. The results of the study showed that the best surface roughness in the finish cut of the spherical surface was obtained using upward pick feed machining.

A Study on Changes in Impervious Surface Area Rate at Administrative Units for Gyeongsangnam-do (경상남도 행정구역별 불투수면적률 현황 및 변화 연구)

  • Kim, Hyeonjoon;Choi Yoonhee;Kim, Hakkwan;Jang, Min-Won
    • Journal of Korean Society of Rural Planning
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    • v.29 no.4
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    • pp.117-125
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    • 2023
  • This study aimed to analyze the recent status and changes in impervious surface areas and their ratios across regions in Gyeongsangnam-do, providing fundamental data for regional development and impervious surface management. Based on the 'Guidelines for Calculating Water Cycle Management Indicators for Nonpoint Pollution Source Control(Ministry of Environment)', we processed the land characteristics survey map(shapefile) from 2018 and 2022 to analyze impervious surface area and their rates by administrative boundaries. The impervious surface area in Gyeongsangnam-do increased from 75,652 ha in 2018 to 81,055 ha in 2022, with the rate rising by 0.51% from 7.18% to 7.69%. The average of impervious surface area across 545 eupmyeon units expanded by approximately 9 ha, from 139.8 ha in 2018 to 148.8 ha in 2022, with the rate increasing by 0.71%. Concurrently, the whole population declined by 2.8% while the number of households surged by 6.4%, correlating with the growth in impervious areas. Despite population decreases, factors such as population migration, increased household fragmentation, new residential developments, and industrial facility expansions have consistently contributed to the rise in impervious surface area. Notably, even in areas with high impervious surface area rate, significant disparities existed between urbanized areas and predominantly rural regions. Furthermore, about 333 units(61% of the whole eupmyeons), showed negligible changes in their impervious surface area rate, with an increase of less than 0.5%.

Sensitivity of Dimensional Changes to Interfacial Friction over the Definite Range of Friction Factor in Ring Compression Test (링 압축시험에서 마찰인자 구간별 치수 변화의 민감도)

  • Lim, J.Y.;Noh, J.H.;Hwang, B.B.
    • Transactions of Materials Processing
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    • v.19 no.8
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    • pp.494-501
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    • 2010
  • The main objective of this study is to examine the sensitivity of calibration curves of FEA of ring compression test to frictional shear factor. Ring compression test has been investigated by measuring dimensional changes at different positions of ring specimen and they include the changes in internal diameter at the middle and top section of the specimen, outer diameter at the middle and top section, surface expansion at the top surface, respectively. Initial ring geometries employed in analysis maintain a fixed ratio of 6 : 3 : 2, i.e. outer diameter : inner diameter : thickness of the ring specimen, which is generally known as 'standard' specimen. A rigid plastic material for different work-hardening characteristics has been modeled for simulations using rigid-plastic finite element code. Analyses have been performed within a definite range of friction as well as over whole range of friction to show different sensitivities to the interfacial friction for different ranges of friction. The results of investigation in this study have been summarized in terms of a dimensionless gradient. It has been known from the results that the dimensional changes at different positions of ring specimen show different linearity and sensitivity to the frictional condition on the contact surface.