• Korean Journal of Ichthyology
• /
• v.10 no.2
• /
• pp.231-240
• /
• 1998

The characteristics of cranium, vertebral column and fin supports of Acanthorhodeus gracilis were examined. The fish did not have a fontanell in cranium nor process of supraethmoid. It had double orbitosphenoids and a basioccipital process developed from anterior portion of basioccipital. It had a high and triangular dorsal process on supraoccipital. In the urohyal, hypohyal attachment was bifurcated and horizontal and vertical plate were in an elongated rhombus shape with posterior edge pointed. It had teeth of 1-rowed, 5/5 and 4 free teeth. The fish did not have a coracoid foramen on shoulder girdle. It does not have a uroneural on ural centrum. It had a long and slender posterior process of pelvic bone. It had a large and flat supraneural. The fish had 14 or 15 interneural spines, of which the 1st, 2nd, 3rd and 4th had single basiosts and the rest had double basiosts. It had 11 or 12 interhemal spines, of which the 1st, 2nd, 3rd and 4th had single basiosts and the rest had double basiosts.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.193-196
• /
• 2008

The vortical structures in a turbulent boundary layer (TBL) developed over a flat plate have been investigated experimentally. The flow conditions tested in this study were Re$_{\theta}$ = 3700, Re$_{\delta}$ = 11${\times}$105 and the shape factor H = 1.3. Instantaneous velocity fields in the streamwise-wall-normal planes were measured by using a dynamic PIV system. A trip-wire and sandpapers were placed behind the leading edge to promote the turbulent transition. 1000 velocity fields were obtained consecutively with a time interval of 1 millisecond. Streamwise u-velocity components were temporally averaged in the measuring plane. In addition, 2000 velocity fields were obtained randomly and ensemble-averaged to get the fully-developed turbulent characteristics. Profiles of the normalized u-component, turbulent intensities and Reynolds shear stress were evaluated. The structures of spanwise vortices were extracted from the instantaneous velocity fields by determining the swirling strength, ${\lambda}_{ci}$. The wall-normalized locations of vortices were temporally averaged in the measuring plane with respect to their rotational direction. The correlations between the temporally averaged u and the temporally averaged $y^+$ of vortices were evaluated. For the case of positive vortices, the correlation is not significant. However, the negative vortices show a strong negative correlation. The y-location of negative vortices tends to increase, as the averaged u decreases and vice versa. These findings indicate that the number of negative vortices in the outer layer increases during the outward bursting events.

• Fashion & Textile Research Journal
• /
• v.19 no.4
• /
• pp.385-399
• /
• 2017

This study will broaden the application of doll costume product with historical characteristics and the image of unlined cheollik in the $17^{th}$ century period of transition during the Joseon Dynasty. Historical design sources were extracted from old documents and precedent studies. Unlined cheollik of Shin Gyeong-yu, meritorious retainer, were selected as main reference-relic because of various fabric, preserved conditions and definite shape. 'Baby doll' was selected as main model because of consumer preferences and awareness. Design sources from unlined cheollik in the early $17^{th}$ century were about a 1:2 ratio of upper and under parts, removable separated doori-somae, knife-shaped collar (outside), projected square collar (inside), long pleats line, side slit, traditional flat fell seam sewing. Trapezoidal side line, round waistline, and thin fabric were applied in designs because of toddler-body of doll model. Three designs were produced in step 1: Cheollik A focusing on the historical remake (traditional type), Cheollik B with belt and side slit (crossover type), and Cheollik C with back- opening (modern type). In step 2, interview with fashion major student was conducted to increase the utility of designs. As a result, modern trend sources (frill, velcro, round armhole line, slope of sleeves, and floral pattern) were reflected in Cheollik B, C. Finally, three doll cheollik and cheollik-styled doll apron sample were produced. Various versions must be suggested in the study of doll costume products with traditional sources that balance historical characteristics and practicality to improve customer satisfaction.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.20 no.12
• /
• pp.4013-4026
• /
• 1996

A numerical simulation has been carried out for the jet impinging on a flat plate and a semi-circular concave surface. In this computation finite volume method was employed to solve the full Navier-Stokes equation based on a non-orthogonal coordinate with non staggered variable arrangement. The standard k-.epsilon. turbulent model and low Reynolds number k-.epsilon. model(Launder-Sharmar model) with Yap's correction were adapted. The accuracy of the numerical calculations were compared with various experimental data reported in the literature and showed good predictions of centerline velocity decay, wall pressure distribution and skin friction. For the jet impingement on a semi-circular concave surface, potential core length was calculated for two different nozzle(round edged nozzle and rectangular edged nozzle) to consider effects of the nozzle shape. The result showed that round edged nozzle had longer potential core length than rectangular edged nozzle for the same condition. Heat transfer rate along the concave surface with constant heat flux was calculated for various nozzle exit to surface distance(H/B) in the condition of same jet velocity. The maximum local Nusselt number at the stagnation point occurred at H/B = 8 where the centerline turbulent intensity had maximum value. The predicted Nusselt number showed good agreement with the experimental data at the stagnation point. However heat transfer predictions along the downstream were underestimated. This results suggest that the improved turbulence modeling is required.

• Smart Structures and Systems
• /
• v.26 no.5
• /
• pp.657-666
• /
• 2020

A rotational pulse-echo ultrasonic propagation imager that can inspect cylindrical specimens for material nondestructive evaluations is proposed herein. In this system, a laser-generated ultrasonic bulk wave is used for inspection, which enables a clear visualization of subsurface defects with a precise reproduction of the damage shape and size. The ultrasonic waves are generated by a Q-switched laser that impinges on the outer surface of the specimen walls. The generated waves travel through the walls and their echo is detected by a Laser Doppler Vibrometer (LDV) at the same point. To obtain the optimal Signal-to-Noise Ratio (SNR) of the measured signal, the LDV requires the sensed surface to be at a right angle to the laser beam and at a predefined constant standoff distance from the laser head. For flat specimens, these constraints can be easily satisfied by performing a raster scan using a dual-axis linear stage. However, this arrangement cannot be used for cylindrical specimens owing to their curved nature. To inspect the cylindrical specimens, a circular scan technology is newly proposed for pulse-echo laser ultrasound. A rotational stage is coupled with a single-axis linear stage to inspect the desired area of the specimen. This system arrangement ensures that the standoff distance and beam incidence angle are maintained while the cylindrical specimen is being inspected. This enables the inspection of a curved specimen while maintaining the optimal SNR. The measurement result is displayed in parallel with the on-going inspection. The inspection data used in scanning are mapped from rotational coordinates to linear coordinates for visualization and post-processing of results. A graphical user interface software is implemented in C++ using a QT framework and controls all the individual blocks of the system and implements the necessary image processing, scan calculations, data acquisition, signal processing and result visualization.

• The Journal of the Korea Contents Association
• /
• v.16 no.3
• /
• pp.72-80
• /
• 2016

There are various methods of developing latent fingerprints from evidence found at crime scenes. Crime scene investigators should choose appropriate techniques among them depending on the conditions of the evidences. In this study, we compared the three methods using forensic light sources to develop latent fingerprints on multi-colored surfaces. We selected the various samples according to color, shape and texture of the surfaces and developed the latent fingerprints using fluorescent powder, IR(Infrared) photography and Episcopic Co-axial Illumination. Fluorescent powder was highly effective on all surfaces. IR photography was also effective, but only on the not dark surfaces. Episcopic Co-axial Illumination was effective only on the flat and polished surfaces. Although fluorescent powder was fine regardless of the characteristics of the surfaces, IR photography was better on certain surfaces.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.9
• /
• pp.1183-1192
• /
• 2001

The numerical simulation has been conducted for the investigation of flow and heat transfer characteristics of an oblique impingement jet injected to a flat plate. The finite volume method was used to discretize the governing equations based on the non-orthogonal coordinate with non-staggered variable arrangement. The $textsc{k}$-$\varepsilon$-ν(sup)'2 turbulence model was employed to consider the consider the anisotropic flow characteristics generated by the impingement jet flow. The predicted results were compared with the experimental data and those of the standard $textsc{k}$-$\varepsilon$ turbulence model. The results of the $textsc{k}$-$\varepsilon$-ν(sup)'2 model showed better agreement with the experimental data than those of the standard $textsc{k}$-$\varepsilon$ model. In order to get the optimum condition, the flow and temperature fields were calculated with a variation of inclined angle($\alpha$=30$^{\circ}$~90$^{\circ}$) and the distance between the jet exit and impingement plate-to-diameter (L/D=4~10) at a fixed Reynolds number(Re=20,000). For a small L/D, the near-peak Nusselt numbers were not significantly effected by the inclined angle. The near-peak Nusselt numbers were not significantly affected by the L/D in the case of a large $\alpha$. The overall shape of the local Nusselt numbers was influenced by both the jet orifice-to-plate spacing and the jet angle.

• Progress in Medical Physics
• /
• v.28 no.1
• /
• pp.33-38
• /
• 2017

Creating individualized build-up material for superficial photon beam radiation therapy at irregular surface is complex with rice or commonly used flat shape bolus. In this study, we implemented a workflow using 3D printed patient specific bolus and describe our clinical experience. To provide better fitted build-up to irregular surface, the 3D printing technique was used. The PolyLactic Acid (PLA) which processed with nontoxic plant component was used for 3D printer filament material for clinical usage. The 3D printed bolus was designed using virtual bolus structure delineated on patient CT images. Dose distributions were generated from treatment plan for bolus assigned uniform relative electron density and bolus using relative electron density from CT image and compared to evaluate the inhomogeneity effect of bolus material. Pretreatment QA is performed to verify the relative electron density applied to bolus structure by gamma analysis. As an in-vivo dosimetry, Optically Stimulated Luminescent Dosimeters (OSLD) are used to measure the skin dose. The plan comparison result shows that discrepancies between the virtual bolus plan and printed bolus plan are negligible. (0.3% maximum dose difference and 0.2% mean dose difference). The dose distribution is evaluated with gamma method (2%, 2 mm) at the center of GTV and the passing rate was 99.6%. The OSLD measurement shows 0.3% to 2.1% higher than expected dose at patient treatment lesion. In this study, we treated Mycosis fungoides patient with patient specific bolus using 3D printing technique. The accuracy of treatment plan was verified by pretreatment QA and in-vivo dosimetry. The QA results and 4 month follow up result shows the radiation treatment using 3D printing bolus is feasible to treat irregular patient skin.

• The Journal of the Korea Contents Association
• /
• v.11 no.3
• /
• pp.201-210
• /
• 2011

Discussion on restoration of Yi Sun-sin's Geobukseon used in sea battles of Imjin War continues. This is because no historical records which we can understand external and internal structure of Geobukseon used in Imjin War do not remain until now. The Geobukseon currently restored based on pictures of woodprint of Jella-jwasuyeong and Tongjaeyeong Geobukseon in Yi-chungmugong Jeonseo published by king's command in the 19th year (1795) of King Jeongjo, but two Geobukseons were built 203 years after Imjin war and not the same as that of Imjin War. Geobukseon that was built by Yi Sun-sin in Imjin War and restored now has many problems in terms of its structure and shape since they do not accord with the records of the literature at that time. Yi Deok-hong's Picture of Hexangonal Ship, drawing Geobukseon in 1593 for the first time was not in it in the study of Geobukseon, but it agrees with Imjin War in terms of the time and in analysis of the structure through picture interpretation and the relationship between Panokseon, Jella-jwasuyeong, and Tongjaeyeong Geobukseon, the center of the upper part of the roof cover is flat, and iron spikes are stuck in the front, back, left and right. The structure and shapes of Geobukseon in the records at the time of Imjin War.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.38 no.3
• /
• pp.305-320
• /
• 2014

This study identifies the foot shapes of elderly women by classifying foot type according to the 3D shape of the foot and 2D sole type analyzing individual characteristics. The subjects were 295 elderly women over 60 years of age who live in Gwangju. A foot scanner (K&I Technology $Nexcan^{(R)}$) was used to obtain three-dimensional shapes of feet and a flat bad scanner (HP Scanjet G2410) was used to obtain the two-dimensional shapes of soles. The anthropometric measuring items consisted of 59 items estimated on the right foot of each subject. Data were analyzed by various statistical methods such as factor analysis, ANOVA and cluster analysis using the SPSS 19.0 statistical program. To classify the side type of elderly women's feet, three-dimensional measurement data were analyzed for the 27 measurement items using factor analysis and 6 factors were extracted (inside height and side gradient, ankle thickness, toe height and midfoot size, lateral malleolus height, instep, and heel height and gradient). A cluster analysis resulted in three types: 36.5% belonged to Type 1 (high forefoot and high midfoot), 31.1% belonged to Type 2 (high forefoot and low midfoot), and 32.4% belonged to Type 3 (low forefoot and high midfoot). The distribution was relatively even. For the sole, 8 factors were extracted (ball width and medial foot protrusion, lateral foot protrusion, forefoot and hindfoot length ratio, ball gradient, heel size, toe breadth, lateral ball length, and foot length) and a cluster analysis resulted in three Types (Type H, Type D, and Type A). The largest proportion (42.7%) belonged to Type H, which is the same as the elderly men's case.