• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1538-1541
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• 2000

Apenetrating head injury by an arrow is extremely rare being only two cases reported in the literature. We report a case of 12-year-old boy who presented with an arrow lodged at the posterior fossa through nasal nostril. He was slightly drowsy, but neurologically intact except a sixth nerve palsy in the left eye. Brain CT showed no intracerebral hemorrhage. The arrow was entered through the right nostril and the tip was stucked in the left cere-bello-pontine angle through the sphenoid sinus. We removed the arrow without craniotomy since the tip was verified smooth and no cerebral arteries were in contact with the arrow. The patient recovered well without any significant complications. The sixth nerve palsy resolved completely after six months. The verification of the shape of the offending material, a retrograde removal of the arrow in the direction of its line of trajectory, and an identification of adjacent cerebral arteries seem to be important in the management of this type of injury.

• Fashion & Textile Research Journal
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• v.20 no.1
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• pp.63-74
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• 2018

The purpose of this study is to investigate the differences in riding characteristics and helmet wearing conditions between bicycle and PMV riders so that the basis data necessary for the development of suitable helmets for each group is provided. For this purpose, riding characteristics and helmet wearing conditions of bicycle and PMV users were investigated using online survey method and then the survey results were interpreted by in-depth interview conducted for bicycle and PMV users. The online survey results showed that the PMV group showed shorter driving distance and more driving frequency than bicycle group. This short driving distance was due to the limitation of battery capacity of PMVs. Helmet wearing rate was significantly lower in PMV group than in bicycle group, which was associated with relatively low chances to drive long distance on the motorway. In the PMV group, the 'urban helmets' were mainly used, in which the appearance of helmet was priorized, but in the bicycle group, the 'road cycle helmets' were mainly used, in which the light weight or ventilation were priorized. Urban helmets caused stronger pain and more fitting problems than road cycle helmets because the head shapes of Koreans were not properly applied to the helmet design. Since the fitting problem and pain intensity were the important causes that making PMV users not wear the helmets, it is necessary to develop the urban helmets reflecting the head shapes of Koreans in order to increase the helmet wearing rate of the PMV users.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.146-154
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• 2009

In recent tissue engineering field, it is being reported that the fabrication of 3D scaffolds having high porous and controlled internal/external architectures can give potential contributions in cell adhesion, proliferation and differentiation. To fabricate these scaffolds, various solid free-form fabrication technologies are being applied. The solid free-form fabrication technology has made it possible to fabricate solid free-form 3D microstructures in layer-by-layer manner. In this research, we developed a multi-head deposition system (MHDS) and used design of experiment (DOE) to fabricate 3D scaffold having an optimized internal/external shape, Through the organization of experimental approach using DOE, the fabrication process of scaffold, which is composed of blended poly-caprolactone (PCL), poly-lactic-co-glycolic acid (PLGA) and tricalcium phosphate (TCP), is established to get uniform line width, line height and porosity efficiently Moreover, the feasibility of application to the tissue engineering of MHDS is demonstrated by human bone marrow stromal cells (hBMSCs) proliferation test.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.478-484
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• 2004

On 11 June 1991, eggs from the brood stock of small yellow croaker (Larimichthys polyactis) were artificially fertilized using the standard dry method and were hatched. Each of the fertilized eggs (1.1-1.2 mm in diameter) had an oil globule and was transparent and buoyant. The fertilized eggs hatched in a range of water temperatures $(17.5-20.3^{\circ}C)$ 44 hrs after fertilization. The total lengths of the newly hatched larvae were 3.1-3.3 mm, and these hatchlings had 31 myotomes (10+21). Melanophores and yellow-brown chromatophores were concentrated on the head, at the ventral part of the yolk, and in the middle of the tail. Four days after hatching, the larvae completely absorbed the yolk and became flexions of 5.1-5.5 mm in total length. Fifteen days after hatching, one spine (the anterior tip of the maxillary) appeared in the upper jaw and three spines developed at the upper parts of the eyes and on the posterior part of the head. At this stage, the larvae were approximately 8.3 mm long. Thirty-nine days after hatching, juveniles (1.9-3.4 mm in total length) had a pointed tail fin. By 66 days after hatching, the juvenile fish (about 4.0-6.5 mm in total length) were similar to adult fish in body shape. The larvae of L. polyactis could be distinguished from those of L. croacea by two distinct characteristics: the large number of vertebrae (28-29), and a relatively small bony ridge on the occipital region of the head.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.9
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• pp.789-795
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• 2014

In this study, the distribution characteristics of diffusers with various shapes that are installed in an open-type thermal storage system are numerically investigated. Four diffusers are designed to distribute a working fluid evenly through the holes on bifurcated pipes. Three-dimensional steady simulations of incompressible laminar flow are conducted using commercial software (ANSYS-FLUENT). The simulation results show that both the bidirectional header-type diffuser and the H-type diffuser distribute the working fluid evenly whereas both the unidirectional and the bidirectional diffusers distribute the working fluid unevenly. The results also show that the H-type diffuser requires a higher head of pump than the bidirectional header-type diffuser. Therefore, the bidirectional header-type diffuser is recommended for use because it enables even distribution of the working fluid and requires a low head of pump.

• Applied Microscopy
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• v.41 no.2
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• pp.117-122
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• 2011

Sperm morphology of Pipistrellus savii velox was examined by transmission electron microscope. The sperm head of P. savii velox was bullet in shape. The sperm head was 3.1 ${\mu}m$ in length, whose posterior 3.0 ${\mu}m$ was occupied by a nucleus with 1.8 ${\mu}m$ in width. The segmented columns were about 14~15 in number. The total number of mitochondrial gyres was 57. Number of 1, 5, and 6 of the outer dense fibers were larger than the others. A fibrous sheath and longitudinal column of the principal piece were evidence, but the fibrous sheath was not seen at the end piece. In the present study, the length of the sperm head of P. savii velox were very shorter than those of other bats.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.9-18
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• 2011

In this paper, we propose a method which recognizes human activity using model-based gaze direction estimation in an indoor environment. The method consists of two steps. First, we detect a head region and estimate its gaze direction as prior information in the human activity recognition. We use color and shape information for the detection of head region and use Bayesian Network model representing relationships between a head and a face for the estimation of gaze direction. Second, we recognize event and scenario describing the human activity. We use change of human state for the event recognition and use a rule-based method with combination of events and some constraints. We define 4 types of scenarios related to the gaze direction. We show performance of the gaze direction estimation and human activity recognition with results of experiments.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.193-201
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• 2006

We researched the reproductive ecology of pale chub, Zacco platypus that inhabits Gajeong-cheon and Wonju-cheon that are a tributary to the Han river. The nuptial organ was formed on the head part, the anal fin and the tail part in male, the change of nuptial color was outstanding. By their changing body shape, the anal fin was extended and body depth came to be high during the spawning season in both sexes. Territorial male of defending behavior were head butting, rotated fighting, parallel swimming, biting and expelling. After pale chub located himself from the upper of the female that was approached to the side parallelling with the female, male and female spawned digging sand with their anal fin by vibrating and any parental care of the eggs was not taken. The spawning interval and lasting time were relevant to individuals density of spawning ground.

• Korean Journal of Bronchoesophagology
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• v.18 no.2
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• pp.49-55
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• 2012

Background and Objectives This study was conducted to gather three dimensional images from computed tomogram in detecting and gaining information about fish bones. Materials and Methods Thirty-nine fish bones and 2 chicken leg bones were used. Bones sandwiched between the cotton sheets were placed into the 3 plastic boxes. Computed tomogram of the bones in the boxes were reconstructed three-dimensionally by Xelis (Infinitt, Korea) to make images of MPR, MIP and VR images. The images were compared with real chicken bones and fish bones as to possibility of detection, finding of location and orientation, and evaluation of shape and calculation of size. Results All 41 bones were detected in all reconstructed images. Distance to the bones from reference point can be measured and orientation can be checked. Shapes were similar between matched images of all real bones. Conclusion The results indicate the usefulness of 3D reconstruction technique in getting informations about fish bones.

• Journal of ILASS-Korea
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• v.26 no.3
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• pp.127-134
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• 2021

Fire sprinkler initial spray was analyzed by Large eddy simulation (LES) and Volume of Fluid (VoF) integrated method. The IsoAdvector geometric VoF was used to identify the liquid-gas interface clearly even with the large Courant-Friedrichs-Lewy number. To reduce the computational costs, sector meshes and Adaptive Mesh Refinement up to level 3 were used. Base mesh size was 1 mm, which is roughly equivalent to the initial sprinkler droplet. Top surface radius of boss and deflector size were modified to investigate the effects of sprinkler head design on primary breakup process. When top surface radius of boss was increased, vertical liquid sheet was formed. This phenomenon reduced the sheet breakup radius, sheet thickness and velocity. Due to reduced liquid sheet thickness, a large amount of ligaments was created from the liquid sheet. As a result, there was a dramatic decrease in volume per surface area, indicating an increase in breakup process. Spray pattern viewed in radial direction also changed when top surface radius of boss increased. When top surface radius of boss was increased, a T-shaped pattern was observed while a V-shaped pattern was observed in all other cases. When the deflector size increases, the spray pattern remains V-shaped, even if the top surface radius of boss increased. Further studies on promoting atomization of the water supplied to the lower part of the sprinkler head in the T-shape pattern should be conducted.