• The Journal of the Korea Contents Association
• /
• v.12 no.8
• /
• pp.380-387
• /
• 2012

A complex seismic survey, which is nondestructive inspection, is used often recently in estimating the location of reclaimed cultural assets. Such a method is the best way to estimate the location of cultural assets most effectively in a short time at a construction site. This study estimated the reclamation location of a cultural asset by using magnetic gradient survey, earth resistivity survey, and ground penetrating radar survey (GPR) in order to figure out the distribution territory in the area with possibility of creation of reclaimed cultural assets in the past. As a result, it was located at +15m on the X axis and +90m on the Y axis on the floor plane coordinate of the study target area. It was shown that the major axis is about 20m long in the north-northeast direction and the width is about 5m. The depth of development distribution of anomaly zone was estimated as about 1.5~3.0m. Geophysical survey is expected to be used as a efficient and accurate way to excavate the reclaimed cultural assets in future.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2451-2456
• /
• 2003

In biological cell manipulation, manual thrust or penetration of an injection pipette into an egg is currently performed by a skilled operator, relying only on visual feedback information. Massive load of various micro injection of either genes, fluid or cells in the postgenomic era calls a more reliable and automatic micro injection system that can test hundreds of genes or cell types at a single experiment. We initiated to study cellular force sensing in zebrafish eggs as the first step for the development of a more controllable micro injection system by any inexperienced operator. Zebrafish eggs at different developmental stages were collected and an integrated biomanipulation system was employed to measure cellular force during penetrating the egg envelope, the chorion. First of all, the biomanipulation system integrated with cellular force sensing instrument is implemented to measure the penetration force of cell membranes and characterize mechanical properties of zebrafish embryo cells. Furthermore, implementation of cellular force sensing system and calibration are presented. Finally, the cellular force sensing of penetrating cell membranes at each developmental stages was experimentally performed. The results demonstrated that the biomanipulation system with force sensing capability can measure cellular force at real-time while the injection operation is undergoing. The magnitude of the measured force was in the range of several hundreds of uN. The precise real-time measurement should provide the first step forwards for the development of an automatic and reliable injection system of various materials into biological cells.

• Journal of Korean Neurosurgical Society
• /
• v.61 no.2
• /
• pp.180-185
• /
• 2018

Objective : Many lumbosacral fixation techniques have been described to offer a more screw-bone purchase. The forward anatomical fixation parallel to the endplate is still the most preferred method. Literature revealed little knowledge regarding the mechanical stability of lumbosacral trans-endplate fixation compared to the traditional trans-pedicular screw fixation method. The aim of this study is to assess the pull-out strength of lumbosacral screws penetrating the end plate and comparing it to the conventional trans-pedicular screw insertion method. Methods : Eight lumbar and eight sacral vertebrae, with average age 69.4 years, Left pedicles of the 5th lumbar vertebrae were used for trans-endplate screw fixation, group 1A, right pedicles were used for anatomical trans-pedicular screw fixation, group 1B. In the sacral vertebrae, the right side S1 pedicles were used for trans-endplate fixation, group 2A, left side pedicles were used for anatomical trans-pedicular screw fixation, group 2B. The biomechanical tests were performed using the axial compression testing machine. All tests were applied using 2 mm/min traction speed. Results : The average pull-out strength values of groups 1A and 1B were $403.78{\pm}11.71N$ and $306.26{\pm}17.55N$, respectively. A statistical significance was detected with p=0.012. The average pull-out strength values of groups 2A and 2B were $388.73{\pm}17.03N$ and $299.84{\pm}17.52N$, respectively. A statistical significance was detected with p=0.012. Conclusion : The trans-endplate lumbosacral fixation method is a trustable fixation method with a stronger screw-bone purchase and offer a good alternative for surgeons specially in patients with osteoporosis.

• The Journal of Engineering Geology
• /
• v.19 no.1
• /
• pp.9-14
• /
• 2009

In this work applicability of a sharp-interface model to well-scale problems is examined. In coastal areas one of the main concerns in groundwater development is saltwater intrusion. To determine the saltwater intrusion at a well one needs to evaluate the saltwater content from a pumping well. We conducted laboratory sand-tank experiments to determine if a sharp-interface model can simulate the saltwater content of a pumping well. Lateral saltwater intrusion experiments and freshwater lens experiments are conducted. A partially penetrating well and a fully penetrating well are used. Comparison between numerical results and observation results indicates that the sharp-interface model can determine saltwater contents reasonably well. We conclude that a sharp-interface model can be applied to well-scale groundwater flow problems in coastal areas.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.6
• /
• pp.496-499
• /
• 2014

The present study investigated variations in soil microbial communities and the chemical properties of forest soils by differing amounts of penetrating sunlight. The soil temperature was significantly higher in higher light-penetrated soils. Higher light-penetrated soils (LP70) showed significantly more fungal communities than the lower light-penetrated soils (LP40 and LP50) (p < 0.05). The $NH_4$-N concentration in LP70 was significantly lower than those of LP40 and LP50, whereas the other chemical properties showed no significant difference among the soils. The cy19:0 to $18:1{\omega}7c$ ratio was significantly lower in LP70 than in LP 40 and LP50 showing the negative correlation of light level with microbial stresses (p < 0.05). The soil microbial communities and the chemical properties that showed positive eigenvector coefficients for PC1 were the fungi to bacteria, fungi, arbuscular mycorrhizal fungi, and Gram-positive bacteria, whereas negative eigenvector coefficients were found for $NH_4$-N, actinomycetes, Gram-negative bacteria, and bacteria. Consequently, the amount of penetrating light was responsible for microbial compositions in the forest soils in correlation with the concentration of $NH_4$-N and soil temperature.

• Journal of Trauma and Injury
• /
• v.25 no.2
• /
• pp.57-62
• /
• 2012

Gunshot wounds are rare in Korea, but they have tended to increase recently. We experienced an interesting case of penetrating gunshot injuries to the cervical spine with migration the fragments of the bullet within the dural sac of the cervical spine, so discuss the pathomechanics, treatment and complications of gunshot wounds to the spine and present a review of the literature. A 38-year-old man who had tried to commit suicide with a gun was admitted to our hospital with a penetrating injury to the anterior neck. the patient had quadriplegia. A Computed tomography (CT) scan and 3-dimensional CT of the spine showed destruction of the left lateral mass and lamina of the 5th cervical vertebra; the bullet and fragments were found at the level of the 5th cervical vertebra. The posterior approach was done. A total laminectomy and removal of the lateral mass of the 5th cervical vertebrae were performed, and bone fragments and pellets were removed from the spinal canal, but an intradurally retained pellets were not totally removed. A dural laceration was noted intraoperatively, and CSF leakage was observed, so dura repair was done watertightly with prolene 6-0. The dura repair site was covered with fibrin glue and Tachocomb$^{(R)}$. Immediately, a lumbar drain was done. Radiographs included a postoperative CT scan and X-rays. The postoperative neurological status of the patient was improved compared with the preoperative neurological status. however, the patients developed symptoms of menigitis. He received lumbar drainage(200~250 cc/day) and ventilator care. After two weeks, panperitonitis due to duodenal ulcer perforation was identified. Finally, the patient died because of sepsis.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.4
• /
• pp.18-22
• /
• 2011

The Ranking source panel method was used to predict the flow phenomenon of a ship with a goose-neck type bulbous bow penetrating the free surface. The non-linearity of the free surface boundary condition was fully satisfied using an iterative calculation method, and the raised panel method was adopted to obtain a more stable solution at each iteration step. The panel cutting method was applied to generate a hull calculation grid at each iteration step, including the first step. At that time, the nose of the goose-neck type bulbous bow was divided by the free surface and the free surface panel was modified at each iteration step using the variable free surface panel method. Numerical calculations were performed to investigate the validity and efficiency of the applied numerical algorithm using the 3600 TEU container carrier. The computed wave resistance coefficients were compared with the experimentally achieved residual resistance coefficients.

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

• Journal of Trauma and Injury
• /
• v.24 no.1
• /
• pp.48-51
• /
• 2011

Powered by compressed air, a nail gun is an essential alternative tool to a hammer on any construction site. This useful machine launches nails at high speed, automatically embedding them in a piece of wood in only a fraction of a second. In spite of its convenience, life-threatening and fatal nail gun injuries can occur when a nail gun is misused, such as in a suicide attempt, or when the operator has insufficient training because combustion nail guns are capable of firing projectiles at velocities higher than 150 m per second. Although injuries by nail guns are rarely reported, there have been reports of nail gun injuries to the head and the trachea in Korea. In the emergency room, the authors experienced a patient injured by an accidental shooting of a nail gun while working in construction. In that accident, a nail penetrated the patient's cervical vertebra through the left cheek. This report is aimed at studying medical treatment for patients with penetrating injuries caused by nail guns.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.16 no.4
• /
• pp.263-267
• /
• 2013

In this research, a novel optical measuring methodology for the measurement of oil thickness in seawater is suggested by evaluating the light absorption which is occurred in the process of penetrating through oil layer on seawater. Laser having monochromatic wave is used as a light source and photodiode which can convert the intensity of the light into an electrical signal is applied to measure the intensity of the penetrating light through the oil-water mixtures. In the experiment, bunker C and lubricating oil are used, and three different lasers having different wavelengths are applied and compared for the selection of an optimal light source. As a result, it is observed that in the case of blue laser, the intensity of the light on the optical sensor decreases with an increase in the oil thickness. Through this relation, both the presence of oil and the thickness of oil can be determined.