• Journal of the Optical Society of Korea
• /
• v.20 no.1
• /
• pp.188-191
• /
• 2016

We investigated surface-roughness-dependent optical loss in a plasmonic cavity consisting of a semiconductor nanodisk/silver nanopan structure. Numerical simulations show that the quality factors of plasmonic resonant modes significantly depend on the surface roughness of the dielectric-metal interface in the cavity structure. In the transverse-magnetic-like whispering-gallery plasmonic mode excited in a structure with disk diameter of 1000 nm, the total quality factor decreased from 260 to 130 with increasing root-mean-square (rms) surface roughness from 0 to 5 nm. This quantitative theoretical study shows that the smooth metal surface plays a critical role in high-performance plasmonic devices.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.2
• /
• pp.203-214
• /
• 1998

The purpose of this study is to classify the upper body of women into several kinds of somatotypes, using the method of Surgical Tape and making their shells. The subjects are 53 females 30 to 39 years-old. Fifty-three anthropometric data are measured per shell of bodysurface; six somatotype factors are obtained through principal component analysis and orthogonal rotation by the method of Varimax, Somatotype of women's upper body is achieved by cluster analysis, using the standardized factor score as an independent variable and the FASTCLUS of SAS by Kmeans. The results are as follows: 1. The number of the factors which explain the somatotype is six and those factors comprise 76.12 percent of total variance. Factor 1: related to the size of shape in the front of upper body Factor S: related to the size of shape in the back of upper body Factor 3: related to the type of the upper chest over the chest circumference line Factor 4: related to the length of·the upper body Factor 5: related to the part of the neck Factor 6: related to the type of the lower chest under the chest circumference line 2. Cluster analysis results in classification of upper body into five clusters. Cluster L: the length is the largest and the circumference is small. The part of waist is the largest and widest among surface areas. Cluster 2: Slender body line from chest to waist is characteristic. The length is longer. The part of upper and lower chest is larger among surface areas. Cluster S: the circumference is the smallest and armhole is small. The length and surface area are small. Cluster 4: the circumference and armhole is the largest. The length is the smallest. Cluster 5: the circumference is average and the length is a little long. The body line(silhouette) from chest to waist is curved slightly.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.5
• /
• pp.345-350
• /
• 2014

This study was conducted to investigate the changes in daily surface temperature of red pepper leaf compared to air and soil surface temperature. The maximum, minimum and average daily temperatures of red pepper leaf were 27.80, 11.40 and $19.01^{\circ}C$, respectively, which were lower by 0.10, 7.60 and $3.86^{\circ}C$ than air temperature, respectively, and lower by 15.00, 0.0 and $4.38^{\circ}C$ than soil surface temperature, respectively. Mean deviations of the difference between measured and estimated temperature by the E&E Model (Eom & Eom, 2013) for the air and surface temperature of red pepper leaf and soil were 0.64, 1.82 and $4.77^{\circ}C$, respectively. The relationships between measured and estimated scaled factor of the air and surface temperature of red pepper leaf and soil were very close to the 1:1 line. Difference between air and surface temperature of red pepper leaf showed a linear decreasing function with the surface temperature of red pepper leaf. Difference between soil surface temperature and air and surface temperature of red pepper leaf linearly increased with the soil surface temperature.

• Journal of applied mathematics & informatics
• /
• v.5 no.2
• /
• pp.489-498
• /
• 1998

The influence of observations the on the goodness-of-fit test in maximum likelihood factor analysis is investigated by using the local influence method. under an appropriate perturbation the test statistic forms a surface. One of main diagnostics is the maximum slope of the perturbed surface the other is the direction vector cor-responding to the curvature. These influence measures provide the information about jointly influence measures provide the information about jointly influential observations as well as individ-ually influential observations.

• Korean Journal of Agricultural Science
• /
• v.43 no.4
• /
• pp.656-664
• /
• 2016

Gear reducers are widely used for various agricultural machinery applications such as greenhouses, tractors, and agricultural vehicles. However, thermal deformation and surface pitting at gear tooth flank frequently occur in gear reducers due to high torque. Thus, surface heat treatment of gears is required to improve wear and fatigue resistance. The objective of this study was to simulate the load capacity of the agricultural gear reducer. The simulation was performed for the following three surface heat treatment methods: untreated gears, nitriding heat treatment, and induction hardening method, those mostly used for agricultural gear reducers. The load capacity of the gear reducer was simulated using the safety factor, limit bending stress, and limit contact stress of the gear. The simulation of the load capacity was conducted using KISSsoft commercial software for gear analysis. The main results of simulation test were as follows: first, the nitriding heat treatment resulted in the highest safety factor for bending stress, which was increased about 77% from those of the untreated gears. Second, the induction hardening was the highest safety factor for contact stress, which was increased about 150% from those of the untreated gears. The safety factor for contact stress of the induction hardening was increased about 64% from those of the nitriding heat treatment. The study result suggested that the surface heat treatments could enhance load capacity and that the method of surface heat treatment should be determined based on simulation results for appropriate use scenarios.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.11 no.2
• /
• pp.191-197
• /
• 1987

It has been well known that the fracture mechanics can be applied to large through crack growth. But the growth rate of small surface cracks initiated from a small defect under rotary bending fatigue tests can not be treated as a function of stress intensity factor range. In this paper, to investigate the growth behavior of surface small fatigue cracks in the view-point of both fracture mechanics and strength of materials, the fatigue test has been carried out on two kinds of plain carbon steels with a small surface defect. Applying the concept of the cyclic strain intensity factor range .DELTA. $K_{\epsilon}$/$_{t}$ to the analysis of small surface fatigue crack growth, it is found that the relationship between cyclic strain intensity factor range and crack growth rate shows linear relation on logarithmic coordinates regardless of defect sizes and two kinds of carbon steels.s.s.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.340-340
• /
• 2016

We have prepared alumina (Al2O3) doped zinc oxide (AZO) films by DC magnetron sputtering (MS) technique and obtained higher self surface texturing at a high target angle (f). We have characterized the films and applied it as a front electrode of a single junction amorphous silicon solar cell. At a lower f the deposited films show higher values of optical gap (Eg), charge carriers mobility & concentration, crystallite grain size and wider wavelength range of transmission. At higher target angle the sheet resistance, surface roughness, haze factor etc for the films increase. For f=72.5o the haze factor for diffused transmission becomes 6.46% at 540 nm wavelength. At f=72.5o the material shows a reduction in crystallinity and evolution of a hemispherical-type sub-micron surface textures. A Monte Carlo method (MCM) of simulation of the AZO film deposition shows that such an enhanced self-surface texturing of the films at higher f is possible.

• Geomechanics and Engineering
• /
• v.6 no.1
• /
• pp.17-31
• /
• 2014

This paper investigates the development of failure surfaces induced by an embankment on soft marine clay deposits and the characteristics of such surfaces through numerical simulations and its comparative study with monitoring results. It is well known that the factor of safety of embankment slopes is closely related to the vertical loading, including the height of the embankment. That is, an increase in the embankment height reduces the factor of safety. However, few studies have examined the relationship between the lateral movement of soft soil beneath the embankment and the factor of safety. In addition, no study has investigated the distribution of the pore pressure coefficient B value along the failure surface. This paper conducts a continuum analysis using finite difference methods to characterize the development of failure surfaces during embankment construction on soft marine clay deposits. The results of the continuum analysis for failure surfaces, stress, displacement, and the factor of safety can be used for the management of embankment construction. In failure mechanism, it has been validated that a large shear displacement causes change of stress and pore pressure along the failure surface. In addition, the pore pressure coefficient B value decreases along the failure surface as the embankment height increases. This means that the rate of change in stress is higher than that in pore pressure.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2000.06a
• /
• pp.251-257
• /
• 2000

A numerical simulation of the temperature rise for sliding surface in dry contact is based on Jaeger's formula combined with a calculated heat input. A gear tooth temperature analysis was performed. The pressure distribution has the Hertzian pressure distribution on the heat source. The heat partition factor is calculated along line of action. A Temperature distribution of tooth surface is calculated about before and after profile modification. A Temperature of addendum and deddendum in modified gear have reduced.

• Journal of Advanced Marine Engineering and Technology
• /
• v.25 no.2
• /
• pp.331-337
• /
• 2001

A numerical simulation of the temperature rise for sliding surface in dry contact is based on Jaegers formula combined with a calculated heat input. A gear tooth temperature analysis was performed. The pressure distribution has the Hertzian pressure distribution on the heat source. The heat partition factor is calculated along ling of action. A Temperature distribution of tooth surface is calculated about before and after profile modification. A Temperature of addendum and deddendum in modified gear have reduced.