• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.353-353
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• 2010

Alcohol is a vesatile polar solvent for molecules. As a preparation to deposit large molecules, we studied interaction of solvent molecules on metallic surface. in this work, we report on methanol adsorption on NiAl(110) with scanning tunneling microscopy (STM). These alcohol solvent molecules were deposited by a pulse injection method suitable for deposition of thermally unstable molecules. The injection of liquid alcohol onto the substrate in UHV was performed by using a high-speed solenoid valve with the back-pressure reduced down to 100 Torr. This technique allowed precise control over the amount of dosing of molecules to less than 1 L. Alcohol-induced features, attributed to methoxy, were found on bare NiAl(110) surface.

• Proceedings of the KAIS Fall Conference
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• 2001.11a
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• pp.144-146
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• 2001

The synthesis of injection-molded parts has been done empirically, since it requires profound knowledge about injection molding which is not available to designers through current CAD systems. Appropriate U3 programs for mold design analysis to an existing geometric modeler is used to provide designers, at the initial stage, with comprehensive process knowledge for synthesis, performance analysis and feature-based geometric modeling.

• The Korean Journal of Pain
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• v.12 no.2
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• pp.191-194
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• 1999

Background: Millions of patients with chronic sciatica are still treated with epidural corticosteroids. The efficacy of epidural corticosteroids remains questionable, especially in the failed back surgery syndrome (FBSS). We studied to evaluate outcome for 10 patients with failed back surgery syndrome treated with spinal nerve root block using corticosteroids, hyaluronidase, and local anesthetics. Methods: The affected nerve roots are localized with the help of fluoroscopy and contrast dye. Local anesthetic diluted in 1,500 U hyaluronidase and 40 mg methylprednisolone is injected. A small retrospective pilot group of 10 patients with FBSS was treated. The success rate is evaluated using a visual analogue scale at 1 week and 3 month interval after the last injection. Results: Initially, 7 patients experienced good pain relief; 5 patients suspained pain relief for 3 months. No complications were observed. Conclusions: This technique is worthwhile for patients with FBSS and where epidural fibrosis is suspected to be the pain origin.

• The Korean Journal of Pain
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• v.19 no.1
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• pp.119-122
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• 2006

Upper thoracic back pain can be musculoskeletal in origin or it could be visceral referred pain, which may be indicative of a serious medical condition. We experienced a case of a 55-years-old female patient who complained of upper thoracic back pain for 1 month, which started 10 days after a traffic accident. She described the pain as being a dull, constant nagging sensation with an intensity of 4/10 on the visual analogue scale. Her pain did not subside after trigger point injection of the rhomboid and trapezius muscles. She reported intermittent palpitation, which indicated that the cardiovascular or pulmonary systems were involved. She was diagnosed with pulmonary thromboembolism by the imaging studies. Refractory upper thoracic back pain should be investigated to rule out this treatable, but potentially fatal condition.

• The Korean Journal of Pain
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• v.5 no.1
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• pp.63-68
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• 1992

One hundred and four patients who complained of chest pain or back pain in the region between scapular were studied. In most cases, anatomical location of pain was in the rhomboid or serratus anterior muscle. Hyperactivity of dorsal scapular nerve or long thoracic nerve which innervate those muscles was thought to be responsible for the pain. The hyperactivity of the nerves may be due to the spasm of the scalenus medius muscle which the nerves meet during their course to the rhomboid or serratus anterior muscles. Therefore, spasmolytic treatment including trigger point injection, physical therapy, laser therapy, or NSAIDs may be effective for the treatment of chest pain or back pain.

• The Korean Journal of Pain
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• v.2 no.1
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• pp.78-84
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• 1989

Steroid and local anesthetics were injected into the epidural space through the posterior sacral foramen or lumbar approach in 4 patients for the purposes of relieving severe low back pain and radiculopathy. These patients were referred from other sections dealing with low back pain and radiculopathy, because one could not tolerate the surgical stress due to a heart problem, another two did not want the operation and the last had post-laminectomy status. All patients were satisfied with the results subjectively.

• Design & Manufacturing
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• v.14 no.3
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• pp.8-16
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• 2020

In this study, the vibration signal of the mold was measured and analyzed to monitoring the process time and characteristics during injection molding. A 5 inch light guide plate mold was used to injection molding and the vibration signal was measured by MPU6050 acceleration sensor module attached the surface of fixed mold base. Conditions except for injection speed and packing pressure were set to the same value and the change of the vibration signal of the mold according to injection speed and packing pressure was analyzed. As a result, the vibration signal had a large change at three points: "Injection start", "V/P switchover", and "Packing end". The time difference between "injection start" and "V/P switchover" means the injection time in the injection molding process, and the time difference between "V/P switchover" and "Packing end" means the packing time. When the injection time and packing time obtained from the vibration signal of the mold are compared with the time recorded in the injection molding machine, the error of the injection time was 2.19±0.69% and the error of the packing time was 1.39±0.83%, which was the same level as the actual value. Additionally, the amplitude at the time of "injection start" increased as the injection speed increased. In "V/P switchover", the amplitude tended to be proportional to the pressure difference between the maximum injection pressure and the packing pressure and the amplitude at the "packing end" tended to the pressure difference between the packing pressure and the back pressure. Therefore, based on the result of this study, the injection time and packing time of each cycle can be monitored by measuring the vibration signal of the mold. Also, it was confirmed that the level and trend of process variables such as the injection speed, maximum injection pressure, and packing pressure can be evaluated as the change of the mold vibration during injection molding.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.95-98
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• 2006

LCD-BLU (Back Light Unit) is one of kernel parts of LCD unit. The fabrication method of a 3-D micro mold patterned with micro-lenses for the LGP (Light Guiding Plate), one of the most important parts of LCD-BLU, was presented. Instead of dot pattern made by etching, 3-D optical pattern design with $50{\mu}m$ micro-lens was applied in the present study. The micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP. The positive micro-lens patterned injection mold with different aspect ratios (i.e. 0.3 and 0.4) was fabricated with modified LiGA with thermal reflow process. The brightness of LCD-BLU increased as aspect ratio of micro-lens increased.

• Korea-Australia Rheology Journal
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• v.19 no.3
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• pp.165-169
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• 2007

The light guide plate (LGP) of LCD-BLU (Liquid Crystal Display-Back Light Unit) is usually manufactured by forming numerous dots by etching process. However, the surface of those etched dots of LGP is very rough due to the characteristics of etching process, so that its light loss is relatively high due to the dispersion of light. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched-dot patterned LGP, micro-lens pattern was tested to investigate the possibility of replacing etched pattern in the present study. The micro-lens pattern fabricated by the modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different optical pattern type (i.e. etched dot, micro-lens). Finally, the micro-lens patterned LGP showed better optical qualities than the one made by the etched-dot patterned LGP in luminance.

• Korea-Australia Rheology Journal
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• v.19 no.3
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• pp.171-176
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• 2007

LCD-BLU (Liquid Crystal Display-Back Light Unit) of medium size is usually manufactured by forming numerous dots with $50{\sim}300\;{\mu}m$ in diameter by etching process and V-grove shape with $50\;{\mu}m$ in height by mechanical cutting process. However, the surface of the etched dots is very rough due to the characteristics of the etching process and V-cutting needs rather high cost. Instead of existing optical pattern made by etching and mechanical cutting, 3-dimensional continuous micro-lens of $200\;{\mu}m$ in diameter was applied in the present study. The continuous micro-lens pattern fabricated by modified LIGA with thermal reflow process was tested to this new optical design of LGP. The manufacturing process using LIGA-reflow is made up of three stages as follows: (i) the stage of lithography, (ii) the stage of thermal reflow process and (iii) the stage of electroplating. The continuous micro-lens patterned LGP was fabricated with injection molding and its test results showed the possibility of commercial use in the future.