• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.13-19
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• 2012

The fatalities rate for passenger vehicles, vans, and commercial vehicles is 1.23, 1.90 and 2.46 deaths per 10,000 registered vehicles, respectively. This shows that vans and commercial vehicles are vulnerable compare to passenger vehicles. To evaluate the crashworthiness of van and Light Truck Vehicle(LTV), we carried out frontal offset crash test at 64km/h, 40% overlap as per IIHS(Insurance Institute for Highway Safety). The test result show that LTV is very poor to protect occupant at frontal crash cause there is no safety system such as airbag and pretensioner and front end length(distance from front bumper to steering wheel) is short. One of the van rated as the lowest rating even it is equipped with airbag, cause its safety cage was collapsed during the test. This result shows that the structural integrity is very important in terms of occupant protection.

• Food Science and Preservation
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• v.18 no.1
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• pp.98-102
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• 2011

We evaluated microbial inactivation in chicken cage litter, to ensure microbial safety, using aqueous chloride dioxide. Contamination by coliforms, Escherichia coli, Listeria spp., yeasts and molds, total aerobic bacteria, and Salmonella spp. was detected in fresh cage litter, and microbial populations increased if litters were repeatedly used. Aqueous $ClO_2$ treatment (500 ppm) significantly decreased the populations of coliforms, E. coli, Listeria spp., yeasts and molds, total aerobic bacteria, and Salmonella spp. in all litter samples tested. In particular, aqueous $ClO_2$ treatment on fresh litter reduced the initial populations of coliform, E. coli, Listeria spp., yeasts and molds, and total aerobic bacteria by 4.47, 1.29, 1.23, 3.24, and 5.2 log CFU/g, respectively. In addition, when litters used for 1 and 5 weeks were tested, treatment significantly reduced microbial populations. The results suggest that aqueous $ClO_2$ treatment is useful to reduce microbial hazards in chicken cage litter and to improve the microbial safety of slaughtered chickens.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.201-202
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• 2008

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.348-356
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• 2011

Objective : The safety and efficacy of various fusion substitutes in pyogenic osteomyelitis has not been investigated. We evaluated and compared the cadaveric allograft and titanium cages used to reconstruct, maintain alignment and achieve fusion in the management of pyogenic spinal infection. Methods : There were 33 patients with pyogenic osteomyelitis underwent fusion in this study. Fifteen of the 33 patients were operated on by fusion with allografts (cadaveric patella bones) and 18 of those were operated with titanium mesh cages filled with autologous cancellous iliac bone. After the affected disc and vertebral body resection with pus drainage, cadaveric allograft or titanium cages were inserted into the resected space. Posterior transpedicular screw fixation and rod compression in resected space, where cadaveric allograft or titanium cages were inserted, was performed to prevent the malposition in all patients except in 1 case. Recurrent infection was identified by serial erythrocyte sedimentation rate and cross reactive protein follow-up. Osseous union and recurred infection available at a minimum of 2 years following operation was identified. The amount of kyphosis correction and the subsidence were measured radiographically. Results : Spinal fusion was achieved in 29 of 33 patients. In the cadaveric allograft group, 93.3% of patient (14 of 15) showed the osseous union while 83.3% of patient (15 of 18) in the titanium cage group showed union. Subsidence was noted in 12 of the patients. Twelve patients (36.3%) showed unsettling amounts of subsidence postoperatively whereas 46.6% of patients in the cadaveric allograft group and 37.7% of patients in the titanium cage group showed similar subsidence, respectively. There were statistical difference in the fusion rate (p=0.397) and subsidence rate (p=0.276) between the two groups. There was significant statistical difference in the postoperative improvement of segmental kyphosis between the two groups (p=0.022), that is the improvement in sagittal alignment was greater in the titanium cage group than in the cadaveric allograft group. There was no case of recurred infection. Conclusion : The cadaveric allograft and titanium cages are effective and safe in restoring and maintaining sagittal plane alignment without increased incidence in infection recurrence in pyogenic osteomyelitis. The postoperative improvement of segmental kyphosis was better in the cage group.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.9-17
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• 2021

This study analyses the load imbalance of the tower crane used in telescoping work for structural safety, owing to the difference in wind speed and balance weight position. This is because wind speed and position of the balance weight have a significant impact on the structural stresses of a tower crane during telescoping work. Therefore, structural analysis was performed on the 290HC model, which is often used at construction sites and has only one cylinder installed. Moreover, two models were classified to determine the load acting on the connecting part of the telescopic cage to slewing platform and the cylinder. Five types of balance weight positions were applied at regular intervals from jibs; moreover, four types of wind load criteria were differently applied. Hence, the telescopic cage columns were destroyed at all balance weight positions at a wind speed of 30 m/s and only at certain locations at a wind speed of 20 m/s. Furthermore, failures occurred for cylinders, torsional, and bending at wind speeds of 30 m/s and 20 m/s, load imbalances above the allowable thresholds considering the safety factor. In addition, the load imbalance in the telescoping work also varied depending on the position of the balance weights. The results of these studies have validated that the current standards of adjusting the appropriate position of the balance weights on the jib are completely valid, with the telescoping work to be executed only at wind speeds of less than equal to 10 m/s.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.357-362
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• 2011

Objective : To report our experience with pyogenic spondylitis treated with anterior radical debridement and insertion of a titanium mesh cage and to demonstrate the effectiveness and safety of the use of a titanium mesh cage in the surgical management of pyogenic spondylitis. Methods : We retrospectively analyzed the clinical characteristics of 19 patients who underwent surgical treatment in our department between January 2004 and December 2008. The average follow-up period was 11.16 months (range, 6-64 months). We evaluated risk factors, cultured organisms, lab data, clinical outcomes, and radiographic results. Surgical techniques for patients with pyogenic spondylitis were anterior radical debridement and reconstruction with titanium mesh cage insertion and screw fixation. All patients received intravenous antibiotics for at least 6 weeks postoperatively, and some patients received oral antibiotics. Results : The infections resolved in all of the patients as noted by normalization of their erythrocyte sedimentation rates and C-reactive protein levels. The mean pain score on a Visual Analog Scale was 7.8 (range, 4-10) before surgery and 2.4 (range, 1-5) after surgery. The Frankel grade was improved by one grade in seven patients. After surgery, the average difference of the angle was improved about $6.96^{\circ}$ in all patients. At the last follow-up, the mean loss of correction was $4.86^{\circ}$. Conclusion : Anterior radical debridement followed by the placement of instrumentation with a titanium mesh cage may be a safe and effective treatment for selected patients with pyogenic spondylitis. This surgical therapy does not lead to recurrent pyogenic spondylitis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.214-224
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• 2004

A large cage system for the purpose of fishes farming in the open sea was influenced by various forces from the ocean environment. The deformation of the cage by these forces affects the safety of the cage itself, as well as that of the cultivated creatures. In this research, theoretical model was established to analyzing dynamic movement influenced by current for cage. Also, to increase the accuracy of calculations, the reduction ratio of flow speed acquired using the flume tank experiment. Applying the reduction ratio of flow speed to the numerical calculation, the calculation values were compared with the measured values in the flume tank experiment using cage model. The results were as follows ; 1. When the flow speed of the flume tank is fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of porosity ratio of netting. 2. When the porosity ratio is fixed, the increase of the velocity of flow which is passed the upper panel side is proportion to the increase of velocity of flow. 3. When the porosity ratio and the flow speed of the flume tank are fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of attack angle. 4. As a result of comparison between the underwater shape by simulation which is applying the reduction ratio of flow speed from the experiment using plane netting and that by model experiment, it was found out that the result of the simulation was very close to that of model gear within ${\pm}$ 5 % error range.

• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.158-164
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• 2019

The interbody fusion cage used to replace the degenerative intervertebral disc is largely composed of titanium-based biomaterials and biopolymer materials such as PEEK. Titanium is characterized by osseointergration and biocompatibility, but it is posed that the phenomenon such as subsidence can occur due to high elastic modulus versus bone. On the other hand, PEEK can control the elastic modulus in a similar to bone, but there is a problem that the osseointegration is limited. The purpose of this study was to implement titanium material's stiffness similar to that of bone by applying cellular structure, which is able to change the stiffness. For this purpose, the cellular structure A (BD, Body Diagonal Shape) and structure B (QP, Quadral Pod Shape) with porosity of 50%, 60%, 70% were proposed and the reinforcement structure was suggested for efficient strength reinforcement and the stiffness of each model was evaluated. As a result, the stiffness was reduced by 69~93% compared with Ti6Al4V ELI material, and the stiffness most similar to cortical bone is calculated with the deviation of about 12% in the BD model with 60% porosity. In this study, the interbody fusion cage made of Ti6Al4V ELI material with stiffness similar to cortical bone was implementing by applying cellular structure. Through this, it is considered that the limitation of the metal biomaterial by the high elastic modulus may be alleviated.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.635-637
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• 2001

The faults of the squirrel cage induction motor is grew increasingly complex as the faults resulting in the shorting of a stator winding and the broken rotor bar or cracked rotor end ring, bearing faults, and so on. The users of electrical machines initially relied on simple protections such as over-current, over-voltage, earth-fault, etc. to ensure safe and reliable operation. but this method cause heavy financial losses and the threat of safety therefore it has now become very important to diagnose faults at there very inception. in this paper, we are going to discuss the detection method of broken rotor bar of squirrel cage induction motor by the motor current signal analysis(MCSA) and the opening terminal voltage signal analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.3
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• pp.12-16
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• 2008

The state of deformation and stress and the structural safety are studied at the main frame composed with car body by the impact of front, offset and overturn in this study. The values of maximum deformation and von-Mises stress in case of offset impact are 2 to 3 times as high as those in case of front or offset impact at the parts of front and middle legs of roll cage. The case of front impact is of the greatest safety as compared with the case of offset or overturn impact. As there is a great stress on the side in case of overturn impact, this value is more than 2 times as low as that in case of offset impact. But there is a great possibility of overturn by the buckling on both sides in case of overturn impact.