• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.197-202
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• 2017

Three-dimensional melanin granules of mummy's hair analyzed using high voltage electron microscopy at 1250kV. The melanin granules in the cortex of mummy's hair located in close proximity to the outer of cortex in the adjacent place of the cuticles. A lot of melanin granule performed in this area. It is a distinguished difference from modern human. While it rotated up to 60 degree counter-clockwise and taken a photo per one degree using high voltage electron microscopy. The melanin granule displayed with long elliptical and variable at the size. The size of granule is measured from $0.3{\sim}0.6{\mu}m$ in minimum diameter and $0.5{\sim}1{\mu}m$ in maximum diameter. Conclusionally, high voltage electron microscope has higher resolution and penetration power than conventional transmission electron microscope that could be load biological thick specimen.

• Journal of Photoscience
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• v.5 no.1
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• pp.1-10
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• 1998

The susceptibility of chilling-resistant spinach plants. and of chilling-sensitive squash plants to photoinhibition was compared in terms of the activity of photosystem II, in relation to the deuce of fatty acid unsaturation of chloroplast membrane lipids. From thylakoid membranes of the plants. monogalactosyl diacylgtycerol, digalactosyl diacylglycerol. sulfoquinovosyt diacylglycerol, and phosphatidylglycerol were seperated as major lipid classes. It was found that the content of cis-unsaturated fatty acids of phosphatidylglycerol was greater by 32% in spinach than that in squash. When leaf disks were exposed to light at 5$\circ$C, 15$\circ$C and 25$\circ$C, photochemical efficiency of photosystem II. measured as the ratio of the variable to the maximum fluorescence of chlorophyll, declined markedly in squash plants, as compared to spinach plants. When leaf disks were exposed to strong light in the presence of lincomycin, an inhibitor of protein synthesis in chloroplasts, photoinhibition was accelerated in the two types of plants. Moreover, lincomycin treatment abolished the differences in the degree of susceptibility to strong light, which had been observed between the two types of plants. When the extent of photoinhibition of photosystem II-mediated electron transport was compared in thylakoid membranes isolated from the two types of plants, there were no differences in the degree of inactivation of photosystem II activity. However, when intact leaf disks were exposed to strong light either at 10$\circ$C or at 25$\circ$C, and then were allowed to recover either at 17$\circ$C or at 25$\circ$C in dim light. chilling-resistant plants such as spinach and pea showed marked recovery from photoinhibition, in contrast to chilling-sensitive plants, such as squash and sweet potato. whose recovery was strongly dependent on the temperature. These findings are discussed in relation to the unsaturation of fatty acids in membrane phosphatidylglycerol. It appears that fatty acid unsaturation of membrane lipids accelerates the recovery of photosystem H from photoinhibition, without affecting the photo-induced inactivation process of photosystem II associated with photoinhibition.

• Korean Journal of Applied Biomechanics
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• v.24 no.3
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• pp.301-308
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• 2014

The purpose of this study was to determine whether there are significant differences in kinematic variables and muscle activities of the thumb between two smartphone holding techniques. Twelve right handed university students(age $25.4{\pm}3.9yrs$, height $176.2{\pm}5.1cm$, weight $75.8{\pm}11.4kg$, hand length $19.2{\pm}1.1cm$) who have no musculoskeletal disorder were recruited as the subjects and had experience in using a smartphone for more than one year. Maximum joint angle, angular velocity, muscular activities were determined for each trial. For each dependent variable, paired t-test was used to determine whether there were significant differences between one hand (OH) and two hands ([TH], ${\rho}$ <.05). The results of this study showed that there were no significant differences between OH and TH in the maximum joint angle of the thumb. The angular velocity of each joint was not statistically significant between OH and TH. The statistical analysis revealed that the main effect of the smartphone holding conditions was significant in the peak normalized muscular activities of FDI and APL. Although smartphone holding technique doesn't affect on mobility and movement of the thumb joint, it may affect on active degree of the thumb and the upper extremity in directly and indirectly.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.9-17
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• 2017

A high degree of precision and accuracy in Gamma Knife Radiosurgery(GKRS) is a fundamental requirement for therapeutical success. Elaborate radiation delivery and dose gradients with the steep fall-off of radiation are clinically applied thus necessitating a dedicated Quality Assurance(QA) program in order to guarantee dosimetric and geometric accuracy and reduce all the risk factors that can occur in GKRS. In this study, as a part of QA we verified the accuracy of single-shot dose profiles used in the algorithm of Gamma Knife Perfexion(PFX) treatment planning system employing Variable Ellipsoid Modeling Technique(VEMT). We evaluated the dose distributions of single-shots in a spherical ABC phantom with diameter 160 mm on Gamma Knife PFX. The single-shots were directed to the center of ABC phantom. Collimating configurations of 4, 8, and 16 mm sizes along x, y, and z axes were studied. Gamma Knife PFX treatment planning system being used in GKRS is called Leksell GammaPlan(LGP) ver 10.1.1. From the verification like this, the accuracy of GKRS will be doubled. Then the clinical application must be finally performed based on precision and accuracy of GKRS. Specifically the width at the 50% isodose level, that is, Full-Width-of-Half-Maximum(FWHM) was verified under such conditions that a patient's head is simulated as a sphere with diameter 160mm. All the data about dose profiles along x, y, and z axes predicted through VEMT were excellently consistent with dose profiles from LGP within specifications(${\leq}1mm$ at 50% isodose level) except for a little difference of FWHM and PENUMBRA(isodose level: 20%~80%) along z axis for 4 mm and 8mm collimating configurations. The maximum discrepancy of FWHM was less than 2.3% at all collimating configurations. The maximum discrepancy of PENUMBRA was given for the 8 mm collimator along z axis. The difference of FWHM and PENUMBRA in the dose distributions obtained with VEMT and LGP is too small to give the clinical significance in GKRS. The results of this study are considered as a reference for medical physicists involved in GKRS in the whole world. Therefore we can work to confirm the validity of dose distributions for all collimating configurations determined through the regular preventative maintenance program using the independent verification method VEMT for the results of LGP and clinically assure the perfect treatment for patients of GKRS. Thus the use of VEMT is expected that it will be a part of QA that can verify and operate the system safely.

• Structural Engineering and Mechanics
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• v.65 no.5
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• pp.573-585
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• 2018

This article presents strain gradient elasticity-based procedures for static bending, free vibration and buckling analyses of functionally graded rectangular micro-plates. The developed method allows consideration of smooth spatial variations of length scale parameters of strain gradient elasticity. Governing partial differential equations and boundary conditions are derived by following the variational approach and applying Hamilton's principle. Displacement field is expressed in a unified way to produce numerical results in accordance with Kirchhoff, Mindlin, and third order shear deformation theories. All material properties, including the length scale parameters, are assumed to be functions of the plate thickness coordinate in the derivations. Developed equations are solved numerically by means of differential quadrature method. Proposed procedures are verified through comparisons made to the results available in the literature for certain limiting cases. Further numerical results are provided to illustrate the effects of material and geometric parameters on bending, free vibrations, and buckling. The results generated by Kirchhoff and third order shear deformation theories are in very good agreement, whereas Mindlin plate theory slightly overestimates static deflection and underestimates natural frequency. A rise in the length scale parameter ratio, which identifies the degree of spatial variations, leads to a drop in dimensionless maximum deflection, and increases in dimensionless vibration frequency and buckling load. Size effect is shown to play a more significant role as the plate thickness becomes smaller compared to the length scale parameter. Numerical results indicate that consideration of length scale parameter variation is required for accurate modelling of graded rectangular micro-plates.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.29-34
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• 2017

In this paper, we report a method of improving the productivity of lead wire fabricated through the rolling process by increasing its linear velocity. The most important point to consider when raising the linear velocity is that the original specifications must still be adhered to. In other words, the dimensional tolerance must be satisfied when increasing the linear velocity of the wire without causing cracks. However, if the linear velocity of the wire is increased, the degree of reduction must also be increased, which causes more damage to the wire and increases the load on its surface. Therefore, we studied a three step rolling process which can satisfy the specifications of the wire produced through the two step rolling process and improve the productivity. In this study, only the roll gap of the three-stage rolling roller is assumed to be a variable, while the other conditions are the same as the field conditions. In addition, through the PIANO (Process Integration, Design and Optimization) tool, the (optimum?) surface roughness and maximum stress are maintained.

• Journal of Korean Academy of Nursing
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• v.4 no.1
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• pp.50-63
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• 1974

Health at infancy and early childhood is considered an important factor for healthy life thereafter. Concept of nursing is inclusive not only of physical care but also psycho-social aspect in order to help achieve maximum state of wellness. Statistical studies reveal concept and structure of family and home tends to change towards nuclear type, ratio of female occupancy tends to increase. These tendencies will influence the method of infants and children. Purpose of this study is to investigate the characteristics of mothers and their children with and without occupation, method of nurturing and analyse data according to various variables, in arnder to give data for care for infants and children. During the period of June 12 though July 22, 1973, 98 mothers and their 224 children; 53 mothers with occupation with 110 children and 45 mothers without occupation with 114 children were Interviewed indirectly through check list. Results of the studies are as follows: 1. Hypothesis 1 ; Tendencies of finger sucking will be greater in children of occupant mothers due to lack of maternal love. Through chi-square examination significant difference is revealed by P>0.05 level, therefore Hypothesis 1 is rejected. (X²=0.24) 3. Hypothesis 2; of occupant mothers tend to have had wanted number of children through family planning. Ratio of wanted versus unwanted children were tested and significant difference is revealed by P<0.05 1eve1. Hypothesis 2 is supported. (X²=8.398). 3. Hypothesis 3: Non-occupant mothers tend to cuddle more while feeding infants. Significant difference Is revealed through Chi-square test by P〈0.05 level. Hypothesis 3 is rejected. (X²=4.34) Conclusion and recommendations: Occupant mothers' higher degree of interest and consideration compared to that of non-occupant mothers in regard to nurturing of their children have been ascertained by this study. These results fight have come up due to the differences of socioeconomic and cultural status of respondents. Further studies on each variable between mothers with and without occupation with similar socio-economic and cultural background are recommended.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.26-32
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• 2010

The purpose of this study is to evaluate the residual stresses at the multi-pass FCA weldment using the finite element analysis (FEA). In order to do it, an H-type specimen was selected as a test specimen. The variable used was in-plane restraint intensity. The temperature distribution at the multi-pass FCA butt weldment was evaluated in accordance with the relevant guidance recommended by the KWJS. The effective conductivity for the weld metal corresponding to each welding pass was introduced to control the maximum temperature below the vaporization temperature of weld metal. The heat flux caused by welding arc was assumed to be applied to the weld metal corresponding to welding pass. With heat transfer analysis results, the distribution of transverse residual stresses was evaluated using the thermo-mechanical analysis and compared with the measured results by XRD and uniaxial strain gage. In thermo-mechanical analysis, the plastic strain resetting at the temperature above melting temperature of $1450^{\circ}C$ was considered and the weld metal and base metal was assumed to be bilinear kinematics hardening continuum. According to the comparison between FEA and experiment, transverse residual stresses at the multi-pass FCA butt weldment obtained by FEA had a good agreement with the measured results, regardless of in-plane rigidity. Based on the results, it was concluded that thermo-mechanical FE analysis based on temperature distribution calculated in accordance with the KWJS’s guidance could be used as a tool to predict the distribution of residual stress of the multi-pass FCA butt weldment.

• The Korean Journal of Zoology
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• v.14 no.2
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• pp.75-84
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• 1971

Genetic analysis of a new wing mutant, Surf wings (Srf), was performed. Mutant flies were extracted from a wild population of Drosophila melanogaster at the vicinity of Atomic Energy Research Institute, Seoul in August-September 1969. 1. The distal half of wings of heterozygotes (Srf/+) turned upwards about 40 degree from body axis, but flying ability was not disturbed. They overlap Cy in low frequency when they are grown below $22^{\circ}C$. This resembles with Si or j series, but wing margins are not rolled and diversed. Postscutellars are erected slightly, but they, in general, are not crossed. Any other external pleiotropic effects were not observed. 2. Penetrance and expressivity of both sexes are not complete. Their extents are variable with sex and temperature. These characters show maximum tendencies when the development is made at $22^{\circ}C$ (female: P = 0.996, E = 0.932, male:P = 0.961, E = 0.698). 3. The preliminary locus of Srf was determined to be 66.8 on the right arm of second chromosome by using recessive maker gene cn bw. 4. The homozygous flies(Srf/Srf) have shown perfect lethality. The heterozygotes (Srf/+), on the other hand, have shown to be viable and fertile. Srf chromosomes are kept in a balanced lethal system with Pm chromosomes which are associated with inversions. Hence, it is partially reasonable to suppose that Srf may persist in a natural population by the same mechanism. 5. Allelism test with Cy was also conducted. The fact that combination with Cy in the trans-phase (+ Srf/Cy +) is viable in contrast to the lethality of Srf/Srf and Pm/Pm indicates that Srf and Cy are not functionally allelic.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.174-179
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• 1986

Augmentin is a formulation of amoxycillin trihydrate and potassium clavulanate, a fused beta-lactam molecule produced by the fermentation of Streptomyces clavuligerus. Most clinically important resistance is due to the production by bacteria of antibiotic destroying enzymes. In the case of penicillins and cephalosporins these enzymes are termed beta-lactamase as they destroy the beta-lectern ring of these antibiotics, completely inactivating them. The presence of clavulanic acid extends the spectrum of amoxycillin to include bet On clinical study of the intravenous Augmentin in the field of thoracic and cardiovascular surgical cases, we selected randomly 30 patients, 21 male and 9 female, age from 13 to 72, in the period from April to December 1985. Among the total 30 patients, 22 were preoperatively infected [11 thoracic empyema, 5 lobar pneumonia, 2 lung abscess, 2 bronchiectasis, one acute pyelonephritis with ureter stone and one rheumatic carditis], and 8 were not infected preoperatively [Table 1, 2]. Of the preoperatively infected group, 11 cases [50%] were culture positive [4 staphylococcus, 3 pseudomonas, 2 Serratia group, and one E. coli], and preoperatively non-infected group [8 cases] revealed expectedly negative findings on bacterial culture. All of the culture positive bacteria were sensitive to Augmentin on disc culture sensitivity test except one case of E. coli. Daily doses of intravenous Augmentin were 2.-1-6.0gm divided in 2-5 injections. Every injection administered [1.2gm at Augmentin dissolved in 20ml distilled water] slowly for more than 20 minutes. Duration of injection was variable according to the clinical conditions from minimum 5 to maximum 31 days. The results of antibiotic treatment with Augmentin and some other antibiotic combinations pre- and postoperatively were subgrouped as EXCELLENT, EFFECTIVE, and FAILURE. Clinical criteria of the therapeutic result were symptomatic, objective and laboratory improvement. 8 cases were excellent, 13 effective, and one failure among the preoperatively infected group, and all 8 cases of the preoperatively non-infected group were effective as pro;hylactive antibiotic therapy. Overall effective ratio was 97% in both subgroup. There was no side effect clinically and laboratory study including liver and kidney function test during and after the I.V. administration of Augmentin. Oral swallow tablets which were administered after discharge from hospital also revealed good effects with some degree of gastrointestinal trouble.