• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.909-916
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• 2019

Radiation therapy of oral and head and neck cancers often involves skin in the therapeutic range, and the use of bolus is frequently used. Dose irregularities provide dose uncertainty in patient application. In this study, the physical properties of patients with gel bolus, poly lactic acid (PLA), and silicon using 3D printing were fabricated. Dose uncertainties arising from the actual radiation dose delivery were measured. As a result, PLA bolus was stable in the Common irregularities. Silicon bolus may be useful for patients with severe irregularities or frequent changes in patient's body shape.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1639-1644
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• 2015

A study on design and structural strength analysis of a positioner in robot overlay welding system of a ball for ball-valves. Turning-unit of positioner modeled, analysis was conducted by assuming the beam. Turning-unit is applied to the stress, it was shown by 366.85MPa when weight of the ball is $9,000kg_f$. This value is higher than the yield strength of the material. Based on the results of previous, it was modeled the turning-unit by modifying. Results of analysis by a modified modeling, The value of stress was confirmed to 296.11MPa. This value is a value lower than the yield strength of the material, it was found to support the weight of the ball.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.11
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• pp.1101-1106
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• 2016

In this thesis, I developed a ball press pushing up equipment to solve the defect that occurs when the ball is inserted to the auto transmission. The ball press pushing up equipment is composed of heating device, thermostat which controls the heating device and the automated insertion device which helps to enhance mass production. This development contributes to quality improvement of domestic automobile production auto transmission part, and also contribute to cost reduction and sales increase for corporations.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.211-217
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• 2010

This study was conducted to investigate a proper method of ball mark repair by comparing the creeping bentgrass recovery speed on golf course green treated by various methods of ball mark repair. Nine general repairing methods were tested and compared; control (no repair, A type), two common methods of USGA (B type) and GCSAA (C type), three methods with fork shaped hand set performing at Korean golf courses (Ansung Benest, D; Sky72, E; Lakeside, F type), and three methods using the repair machine with 6, 8, or 14 teeth (G, H, I type, respectively). Three creeping bentgrass cultivar of 'Penncross', 'T-1', and 'CY-2' were tested in this field experiment. This test was carried out from September to November in 2009 at the nursery on the Seoul Lakeside Golf course. The average speed of turfgrass recovery after various ball mark repairing methods have been ranked as in the order of E, D, C, B, F, I, H, G, and A. The methods of hand practise showed more effective results than repair method using machines. The ball mark recovery speeds of 'Penncross' were in the order of E, D, B, C, F, I, H, and A. In the case of 'T1' and 'CY-2', similar orders were showed as D, E, B, F, C, H, I, A, G and the order of D, E, C, F, B, H, G, I, A, respectively. The ball mark recovery speed among creeping bentgrass cultivar resulted in the order of 'CY-2', 'Penncross', and 'T-1'. The most proper method of ball mark repair was repair method using a hand set tool especially the method of the Sky72 Golf course (E type). At the first, remove a damaged grass area with fork and tap. And then gather the side grasses into the center area with pulling the grasses with fork. After that, make harden and flat on the turf surface by pounding and rolling with the round wooden stick. The final Nstep, water the repaired grass surface. This ball mark repairing practise showed a most rapid and proper recovery method on creeping bentgrass green.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.80-85
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• 2010

BGA 409 chip currently the most as a visual inspection of the exterior inspection is conducted. Human depending on visual inspection of the exterior inspection of the current state of testers, depending on how the test results because the change is difficult to expect reliable results. Therefore, the challenges of visual inspection of BGA solder balls to improve the visual inspection technique was developed. However, BGA solder ball size of the microstructure and the characteristics of the distinction between hard test the accuracy of the fall orientation error has a problem. In this paper BGA solder balls exterior inspection of the accuracy to improve the edge detection algorithm, the complement of features and only the comparison proposed a pattern-matching techniques, based on the characteristics of spatial configuration of the area by improving the standard error of the orientation proposed improvements.

• Journal of Korea Game Society
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• v.7 no.4
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• pp.13-21
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• 2007

Recently, medical advances have been increasing the size of the aged population. With rapidly developing technology, computers are now essential parts in our daily life, and the number of the aged people using computers is also increasing continuously. But user interfaces and contents for the aged people have not yet been developed actively. In this paper, we present a 3D sensory gate-ball game which can be played by the aged people easily. This study is based on 3D graphics and uses a realistic gate-ball stick and balls as interfaces, so it can improve both physical and metal health of the aged people. Because our game is a sensory game, it is easy to play in house without an outdoor playground. In addition, the game provides many interesting situation so that it can raise the participation and interest of the aged people.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.121-124
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• 2008

Tarballs formed by HEBEI SPIRIT oil spill observed in the south-western sea of Korea from December 27 2007. The tarballs were removed by the response party, which Korea Coast Guard became a center of organization. The amounts of removing tarballs form the sea and the coast were 0.345 tons and 1,739 tons, respectively. The number of persons, in order to remove the tar balls from the south-western sea of Korea, counted about 97,000 persons, including 25,000 volunteers. In this paper, we introduced the response methods of tarballs entering into the south-western sea of Korea such as a landing net, meshes and so on.

• Cross-Cultural Studies
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• v.40
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• pp.185-212
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• 2015

Bruno Dumont's film P'tit Quinquin (2014) trends toward 'the new extremism' in contemporary European cinema. This criminal-mystery-comedy film achieves the cinematic recognition of reality in the new extremist way: like typical new extremist films, P'tit Quinquin contains a lot of 'unwatchable' content, including disembodied parts of human body, carcasses, and the body of a boy who has killed himself. The reality, however, remains confidently invisible, despite everything that is visible within the film. In understanding Dumont's attempt to reach cinematic recognition, the relationship between 'the visible' and 'the invisible' is reconsidered. In the context of the film, the relationship between cinema and reality becomes indirect. The reality can be only felt, not seen. The invisible reality can be perceived only as a void, just like the criminal who is unknown even though he is sought after. To reveal this void, the film strives to give its viewers as much explicitly visible content as possible during its 200-minute run. This essay is an interdisciplinary attempt to examine the working and the effects of this cinematic attempt by Bruno Dumont; aspects of film theory, visual anthropology, (inter-)mediology, posthumanism in cultural theory, etc., are related for this purpose.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.2
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• pp.105-112
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• 2006

Purpose: To demonstrate that water bolus in the patient surface can decrease the dose inhomogeneity by patient surface large tissue defect when the surface is in an electron-beam field. And We tried to find a easy way to water control. Methods and Materials: To demonstrate the use of water bolus in the irregular surface clinically, the case of a patient with myxofibrosarcoma of the chest wall who was treated with electrons. We obtained dose distribution using missing tissue option of PINACLE 6.2b (ADAC, USA). We fabricate a Mev-green for water bolus in patient with defect of tissue. Then put the water bolus which is vinyl packed water into the designed Mev-green. We peformed CT scan with CT-simulator. Three-dimensional (3D) dose distributions with and without water bolus in the large irregular chest wall were calculated for a representative patient. Resulting dose distributions and dose-volume histograms of water bolus were compared with missing tissue option and non bolus plans. We fabricate a new water control device. Results: Controlled Water bolus markedly decrease the dose heterogeneity, and minimizes normal tissue exposure caused by the surface irregularities of the chest wall mass. In the test case, The non bolus plan has a maximum target dose of 132%. After applying water bolus, the maximum target dose has been reduced substantially to 110.4%. The maximum target dose was reduced by 21.6% using this technique. Conclusion: The results showed that controlled water bolus could significantly improve the dose homogeneity in the PTV for patients treated with electron therapy using water control device. This technique may reduce the incidence of normal organ complications that occur after electron-beam therapy in irregular surface. And our new device shows handiness of water control.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.203-211
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• 2006

This study was initiated to investigate the difference of playing ability among soccer fields established with natural turfgrass, artificial turf and bare ground. The soccer fields with natural turfgrasses were established with cool-season grass(Kentucky bluegrass 80%+Perennial ryegrass 20%) and zoysiagrass. The artificial turf field was constructed with Konigreen $DV5000^{TM}$. Bare ground was sandy soil. Data such as ball rolling distance and vertical ball rebound were collected at the Sports Science Town of Konkuk University from 2005 to 2006. A ball in the study was Hummel Air Vision #1, certified by KFA(Korea Football Association) in ball pressure of 1.01b. Ball rolling distance was the longest on bare ground(13.6m), followed by artificial grass(11.4m), cool-season grass(7.8m) and zoysiagrass(4.7m). It decreased with lower frequency in use, stronger rigidity and higher density of turfgrass. Vertical ball rebound was the highest on bare ground(1.0m), followed by artificial grass(0.9m), cool-season grass(0.6m) and zoysiagrass(0.4m). It was lower under conditions of low use frequency, strong rigidity, and high density. Both ball rolling distance and vertical ball rebound were not greatly affected by cool-season grass maintained with high intensity of culture by years after establishment. However, zoysiagrass field under low intensity of culture showed longer in ball rolling distance and higher in vertical ball rebound with time after establishment.