• Fire Science and Engineering
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• v.30 no.2
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• pp.106-113
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• 2016

Ultra-high pressure positive displacement pump can discharge high pressure water with mass volume, which depends on periodic changes in volume that made by rotation motor. Its high efficiency of discharge is one of the most strong point of positive displacement pump. Due to its simple system structure, it can be miniaturized and lightened. Positive displacement pump can discharge high pressure with stable flow rate, irrespective of pressure fluctuate. This is the reason that positive displacement pump was used instead of centrifugal pump. In this study, shutoff operating system was developed for positive displacement pump to secure safety of high pressure operate. This shutoff system contains controller system, electronic clutch, and relief valve, and each part is mutual supplementation. Speed test was carried out in order to check operation of controller program and electronic clutch and fluid flow, venting experiment of the relief valve. It was confirmed that segment system of ultra-high pressure positive displacement pump is operated.

• Fire Science and Engineering
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• v.26 no.5
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• pp.85-91
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• 2012

This paper analyzed firefighting officers' use situations such as the use time, maximum working pressure, hose diameter, etc. of fire pumps at fire sites and carried out various performance tests by pressures, hose diameters and quantities of fire pumps based on its results because the waterproof performance criterion for a fire pump installed in a fire engine is different from the operation situations at the site and is not clearly prescribed. As a result of site survey, the site uses a higher pressure than the standard water discharge pressure (0.85 MPa) or the high-pressure water discharge pressure (1.4 MPa) prescribed by the approval Standard of the fire pump performance on fire truck. In addition, as a result of pump performance test, the discharged water flow rate, water discharge pressure, etc. was measured to be very different from the currently prescribed the approval standard depending on the hose diameter and firefighting nozzle, so the result of this study proposes a new standard.

• Archives of Plastic Surgery
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• v.34 no.6
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• pp.796-798
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• 2007

Purpose: Giant cell tumor is the second most common benign neoplasm in upper extremity. Unlike usual chief complaint of painless mass, an atypical case with giant cell tumor presented a distinguishing characteristics of which accompany pain and tenderness and is histologically giant-cell free. Methods: A 31-year-old male patient complained of a rapid growing painful mass on the proximal phalanx of the left ring finger. Under microscopic operation, a $1.6{\times}1.3cm$ sized mass was found to be surrounded by areolar tissue and attached to a tendon sheath, encircling the digital nerve and artery. Diagnostic confirmation was assisted by positive finding in histologic immunohistochemical stain-CD68. Characteristic pathologic finding is an atypical distribution of spindle cells & histiocytes without giant cells in fascicular pattern. Results: Giant cell tumor was carefully removed under microscopic approach, while preserving digital nerve & artery. In postoperative 13th month, the patient presented with a 6mm of static two-point discrimination test, similar to that of the adjacent fingers. Conclusion: We report an atypical case with painful mass on tendon sheath, surrounding the digital nerve and artery that was diagnosed of giant cell tumor, but without giant cells on pathology. This case provides broader understanding of the giant cell tumor that should not only rely its typical findings of the painless mass and positive sign on H&E stain.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.607-612
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• 2010

Purpose: Maxillectomy for malignant tumor resection often leads to functional and aesthetic sequalae. Reconstruction following maxillectomy has been a challenging problem in the field of head and neck cancer surgery. In this article, we described three dimensional midface reconstructions using free flaps and their functional and aesthetic outcomes. Methods: We reconstructed 35 cases of maxillectomy defects using 9 radial forearm free flaps, 7 lattisimus dorsi musculocutaneous free flaps, 6 rectus abdominis musculocutaneous free flaps, 4 fibular osteocutaneous free flaps, and 9 anterolateral thigh free flaps, respectively. We classified post-maxillectomy defects by Brown's classification. 1 Articulation clarity was measured with picture consonant articulation test. Swallowing function was evaluated with the University of Washington quality-of-life Head and Neck questionnaire by 4 steps.2 Aesthetic outcomes were checked to compare preoperative with postoperative full face photographs by 5 medical doctors who did not involve in our operation. Results: The average articulation clarity was 92.4% (100-41.9%). 27 (81.9%) patients were able to eat an unrestricted diet. Aesthetic results were considered excellent in 18 patients (51.4%). Functional results were best in the group reconstructed with fibular osteocutaneous free flap. Considering the range of wide excision, aesthetic results is best in the group reconstructed with anterolateral thigh free flap. Conclusion: The free flap is a useful technique for the reconstruction of the midface leading to good results, both functionally and aesthetically. Especially, because osteocutaneous flap such as fibular osteocutaneous free flap offered bone source for osteointegrated implant, It produces the best functional results. And perforator flap like as anterolateral thigh free flap reliably provides the best aesthetic results, because it provides sufficient volume and has no postoperative volume diminution.

• Archives of Plastic Surgery
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• v.37 no.3
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• pp.289-292
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• 2010

Purpose: Mycobacterium abscessus belongs to the group of rapid-growing atypical mycobacterium. The organism is ubiquitous and is found in soil, dust, and water. Although it rarely causes disease in humans, Mycobacterium abscessus has been associated with soft tissue infection. To the best of our knowledge, this is the first case report of facial soft tissue Mycobacterium abscessus infection in a healthy child in Korea. Methods: A 12-year-old girl presented with an erythematous skin lesion with serous discharge on her chin, which had been present for 3 weeks. On her history, she had a laceration wound on her chin at public bath and the lesion was repaired at emergency department immediately. Although conventional soft tissue infecton treatment, her lesion remains unhealed state and had serous discharge for 2 months. Moreover, we found a 1 cm sized nodular mass on her chin. Therefore we performed excision operation and referred the specimen to the laboratory for microbial and histopathologic study. Results: Pathology report confirmed the mass was enlarged lymph node with chronic necrotizing granulomatous inflammation with central microabscess. Non-Tuberculous mycobacterium identification test through tissue specimen resulted Mycobacterium abscessus. We prescribed clarithromycin for three weeks by oral administration as well as performed wound debridement and mass excision via previous wound. This way, her lesion appeared to be complete healing with minimal scarring. There were no evidence of inflammation sign or palpable mass. Conclusion: Although the prevalence is rare, Mycobacterium abscessus infections of soft tissue should be considered even in a healthy child with a lesion caused by trauma or which fails to respond to conventional treatment.

• Tunnel and Underground Space
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• v.16 no.1 s.60
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• pp.85-94
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• 2006

In this study, scaled model tests were carried out to decide the optimal critical velocity, to prevent back layering in the case of fire in a long traffic tunnel. Realistic estimates were made for the time required for people to escape ken the tunnel and far the time required by the ventilation operator to increase the system speed to full capacity. The analysis, predicts that the emergency ventilation will start about 240 seconds after the tunnel fire. It was also found that prevention of back layering would occur within 4 minutes after fan operation. To find out optimal critical velocity, a 1/50 scaled model tunnel(diameter : 0.2 m and length : 20 m) based on the Froude similarity technique was constructed. Changing $\beta$ values in the Tetzner's equation, smoke propagation was observed. From the experiment, it was concluded that using a $\beta$ value of 0.5 to prevent back layering successfully allowed time for safe evacuation.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.5
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• pp.27-33
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• 2003

G-code, another name of ISO6983, has been a popular commanding language for operating machine tools. This G-code, however, limits the usage of today's fast evolving high-performance hardware. For intelligent machines, the communications between machine and CAD/CAM departments become important, but the loss of information during generating G-code makes the production department isolated. The new standard for operating machine tools, named STEP-NC is just about to be standardized as ISO14649. As this new standard stores CAD/CAM information as well as operation commands of CNC machines, and this characteristic makes this machine able to exchange information with other departments. In this research, the new CNC machine operated by STEP-NC was built and tested. Unlike other prototypes of STEP-NC milling machines, this system uses the STEP-NC file in XML file form as data input. This machine loads information from XML file and deals with XML file structure. It is possible for this machine to exchange information to other databases using XML. The STEP-NC milling machines in this research loads information from the XML file, makes tool paths for two5D features with information of STEP-NC, and machines automatically without making G-code. All software is programmed with Visual $C^{++}$, and the milling machine is built with table milling machine, step motors, and motion control board for PC that can be directly controlled by Visual $C^{++}$ commands. All software and hardware modules are independent from each other; it allows convenient substitution and expansion of the milling machine. Example 1 in ISO14649-11 having the full geometry and machining information and example 2 having only the geometry and tool information were used to test the automatic machining capability of this system.

• Korean Journal of Remote Sensing
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• v.31 no.3
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• pp.267-279
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• 2015

In the development of autonomous vehicles, the importance of LIDAR sensors becomes larger. For sensor selection or algorithm development, it is difficult to test expensive LIDAR sensors mounted on a vehicle under various driving environment. In this study, we developed a simulator that is generally applicable for various vehicle LIDAR sensors based on the generalized geometric modeling of the common processes associated with vehicle LIDAR sensors. By configuring this simulator with the specific sensors being widely used, we performed the data simulation and quality analysis. Also, we applied the simulation data to obstacle detection and evaluated the applicability of the selected sensor. The developed simulator enables various experiments and algorithm development in parallel with hardware implementation prior to the deployment and operation of a sensor.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.62-72
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• 2015

This study investigates the in-situ implementation of bio-regenerated iron mineral catalyst to remove explosive compounds in ground water at a military shooting range in operation. A bio-regenerated iron mineral catalyst was synthesized using lepidocrocite (iron-bearing soil mineral), iron-reducing bacteria Shewanella putrefaciens CN32, and electron mediator (riboflavin) in the culture medium. This catalyst was then injected periodically in the ground to build a redox active zone acting like permeable reactive barrier through injection wells constructed at a live fire military shooting range. Ground water and core soils were sampled periodically for analysis of explosive compounds, mainly RDX and its metabolites, along with toxicity analysis and REDOX potential measurement. Results suggested that a redox active zone was formed in the subsurface in which contaminated ground water flows through. Concentration of RDX as well as toxicity (% inhibition) of ground water decreased in the downstream compared to those in the upstream while concentration of RDX reduction products increased in the downstream.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.403-409
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• 2007

This study was carried out to recommend the systematic improving practice for the effective operation of septic tank, and the evaluation of its BOD and nutrient removal efficiency depending on process, the survey of characteristics of FRP material, and the suggestion of optimum septic tank model within sewage treatment area. The average BOD concentration and BOD removal efficiency of septic tank which was carried out the cleaning periodically in 63.9 mg/L and 77.8%, shows good quality better than the septic tank which was not carried out the cleaning regularly. Maximum load of tensile, flexural and compressive strength increased in proportion to its thickness, and the contents standard 25% of glass fiber required upgrade over than 30%. Configuration and performance for the optimum of the septic tank suggests that over $0.75m^3$ of the effective total volume, adding to over $0.25m^3$ a man for more than 5 men of the treated person, retention time should be within one day. Improving plans about facility and materials quality of the septic tank have an obligation that protective wall ought to install on the concrete bottom and side faces to prevent crumble or transform from loading of the ground or upper part of the structure on the tank setting. And it is eliminated the uneffective resisting pressure and it keeps off circulate imperfect products by strengthening of the test methods such as stretching strength, pressing strength, glass fiber contents and thickness.