• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.79-87
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• 2016

Mobile fish-cage was developed assuming a cage net with an enclosed area, which and estimated the hydrodynamic characteristics of the cage through the model experiment. Flux-shielding plates, installed in the bow were compared with the resistance test carried out by making a hole, bilge keel and stud, and basic block flow rate consisting of the results to a flat surface plate. The experimental results confirmed the improved resistance performance effect of 3~6% in the bilge keel and the stud form. To assess the stability of the fish-cage, evaluation of the stability in accordance with the stability criteria for determining the floating docks had confirmed that it satisfied the static stability performance under operating conditions at sea.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.690-699
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• 2011

A numerical model analysis was performed to analyze the stability of the mooring lines of an automatic submersible fish cage system in waves and currents. The fish cage system consisted of a 12-angled rigid frame, net cage, cover net, 12 upper floats, 12 tanks(for fixed and variable ballast), mooring lines, anchors, and a control station. Simulations were performed with the cage at the surface of the water and at a depth of 20 m. A Morison equation type model was used for simulations of the system in two configurations. The force parameters described both regular and random waves, with and without currents, and their values were input to the model. Mooring tension calculations were conducted on the mooring lines, grid lines and lower bridle lines of the cage. The stability of the mooring lines was checked under both static and dynamic conditions.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1364-1367
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• 2003

These days, spinal interbody arthrodesis using fusion cage is very popular. The cage used for the spinal interbody arthrodesis is mainly inserted from the posterior of the spine. Accordingly, there could possibly occur damages at posterior and results in instability of structure. Moreover, one or two cages are inserted depending on the patients. In this study, it is attempted to evaluate the stability quantitatively by comparing two cases where one and two cages are inserted. For this purpose, a very fine 3-dimensional finite element model of vertebra is generated from the MRI data. From this vertebra model, two models are made: one with one cage and the other with two cages. Finally, finite element analys is performed for these two models and both of the mechanical behaviors are examined In addition, the effect on the stability is evaluated and compared quantitatively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.2
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• pp.201-208
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• 1999

To develop a new fish cage which is required for offshore or moving cage culturing system has been gradually increased against being closely dense of fish cage in shallow water. Though submersible fish cage culturing system is essential technology for converting from shallow water into the offshore, it was pointed out the serious problem about stability of which are sinking and floating state. This study is presented conceptual design of submersible fish cage centered with a mooring steel pile to acquire stability and faculty. Design of mooring steel pile for submersible fish cage culturing system needs to carry out optimal design of mooring steel pile for which much efforts are required. Formulation and optimal design process of submersible fish cage are organized into using Sequential Quadratic Programming method of numerical optimization. For submersible fish cage system centered with a mooring steel pile, process of the optimal design is proposed and the optimal solutions are obtained.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.361-367
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• 2004

The axial compressive strength, relative 3-D stability and osteoconductive shape design of an intervertebral fusion cage are important biomechanical factors for successful intervertebral fusion. Changes in the stress distribution of the vertebral end plate and in cage stability due to changes in the spike shape of a newly contrived box-shaped fusion cage are investigated. In this investigation, the initial contact of the cage's spikes with the end plate and the penetration of the cage's spikes into the end plate are considered. The finite element analysis is conducted to study the effects of the cage's spike height, tip width and angle on the stress distribution of the vertebral end plate, and the micromigration of the cage in the A-P direction. The stress distribution in the end plate is examined when a normal load of 1700N is applied to the vertebra after inserting 2 cages. The micromigration of the cage is examined when a pull out load of l00N is applied in the A-P direction. The analysis results reveal that the spike tip width significantly influences the stress concentration in the end plate, but the spike height and angle do not significantly influence the stress distribution in the end plate touching the cage's spikes. In addition, the analysis results show that the micromigration of the cage can be reduced by adjusting the spike angle and spike arrangement in the A-P direction. This study proposes the optimal shape of an intervertebral fusion cage, which promotes bone fusion, reduces the stress concentration in a vertebral end plate, and increases mechanical stability.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.2
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• pp.193-201
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• 2014

The sea cage in marine aquaculture might be varied such as on the stability and shape in the open sea by environmental factors. To evaluate the stability of net cage structures in the open sea, the physical and numerical modeling techniques were applied and compared with field observations. This study was carried out to analyse the stability and the volume loss which would have an effect on the fish swimming behavior in the octagonal pillar type fish cage under the open sea. As a results, the volume loss ratio of the fish cage as measured using a depth sensor was indicated a value of the 30.3% under the current velocity (1.1m/s). The fish cage should be consisted of a concrete block with a weight over 10 tons, a mooring rope diameter over 28mm PP, and a shackle of 25mm under the current speed of 1m/sec for reasonable stability.

• Journal of Applied Reliability
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• v.14 no.4
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• pp.243-247
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• 2014

The Spinal cage is the cage-shaped implantable medical device used to treat structural abnormalities caused by degenerative intervertebral disks. In order to secure enough space to provide the mechanical stability and the intervertebral fusion, after removing the intervertebral disc, the Spinal cage is transplanted between the intervertebral space. A hammer is used to push the spinal cage into a narrow space during the spinal cage transplant surgery. Due to the impact and pressure, damage occurs frequently on the spinal cage. In this study, a test model is constructed to measure the value of impulse generally applied on the Spinal cage. The figures of internal impulse before and after the improvement of the Spinal cage are then compared to suggest direction to improve the reliability of the spinal cage.

• The Journal of Fisheries Business Administration
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• v.52 no.2
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• pp.33-54
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• 2021

This study is aimed to analyze the economic feasibility of yellowtail culture using the copper alloy net cage in Gyeongsangbuk-do. First of all, in order to evaluate the copper alloy net cage on yellowtail culture, I review the trend on the yellowtail culture industry and research the concept of copper alloy net cage. The copper-alloy net cage is now recognized as an advantages of its system stability, recycling, antibiosis and food safety. The results were summarized as follows: first, there was significant meaning of the profit model of yellowtail culture by the price difference. Second, I analyzed in the economic feasibility of yellowtail culture using the copper alloy net cage, internal rate of return (IRR) was 51.58%, a benefit-cost ratio was shown to be 2.27 and net present value (NPV) was 1,087,337 thousand won, which indicates the economic feasibility of yellowtail culture using the copper alloy net cage is profitable. Finally, in order to improve the economic valuation, it is necessary to focus more on the developing of technology and cost reduction strategy on the copper alloy net cage.

• Journal of Korean Neurosurgical Society
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• v.56 no.4
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• pp.323-329
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• 2014

Objective : Vertebral body replacement following corpectomy in thoracic or lumbar spine is performed with titanium mesh cage (TMC) containing any grafts. Radiological changes often occur on follow-up. This study investigated the relationship between the radiological stability and clinical symptoms. Methods : The subjects of this study were 28 patients who underwent corpectomy on the thoracic or lumbar spine. Their medical records and radiological data were retrospectively analyzed. There were 23 cases of tumor, 2 cases of trauma, and 3 cases of infection. During operation, spinal reconstruction was done with TMC and additional screw fixation. We measured TMC settlement in sagittal plane and spinal angular change in coronal and sagittal plane at postoperative one month and last follow-up. Pain score was also checked. We investigated the correlation between radiologic change and pain status. Whether factors, such as the kind of graft material, surgical approach, and fusion can affect the radiological stability or not was analyzed as well. Results : Mean follow-up was 23.6 months. During follow-up, $2.08{\pm}1.65^{\circ}$ and $6.96{\pm}2.08^{\circ}$ of angular change was observed in coronal and sagittal plane, respectively. A mean of cage settlement was $4.02{\pm}2.83mm$. Pain aggravation was observed in 4 cases. However, no significant relationship was found between spinal angular change and pain status (p=0.518, 0.458). Cage settlement was seen not to be related with pain status, either (p=0.644). No factors were found to affect the radiological stability. Conclusion : TMC settlement and spinal angular change were often observed in reconstructed spine. However, these changes did not always cause postoperative axial pain.

• Journal of Korean Neurosurgical Society
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• v.40 no.6
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• pp.471-475
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• 2006

Complete vertebral tumor resection is important in order to prevent local recurrence. Among the available techniques for total spondylectomy, the total en bloc spondylectomy has been accepted as the most sophisticated one. After a total en bloc spondylectomy, anterior and posterior column reconstruction is mandatory in order to achieve stability. We experienced the usefulness of an expandable cage for anterior column reconstruction especially in this surgery. The chance of cutting the nerve root and damaging the spinal cord is minimized because the size of the expandable cage is initially small enough to be inserted into the anterior column. The technical details of total vertebral body replacement with an expandable cage after an en bloc lumbar spondylectomy are described herein.