• Journal of Power System Engineering
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• v.21 no.3
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• pp.37-44
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• 2017

In this study, failure analysis of the angular pin for molding machines to aluminum component molding was carried out. SM45C steel was used for the angular pin, it was surface hardened by the induction surface hardening heat treatment. The cross section of damaged angular pin was observed, and micro Vickers hardness value from the fractured part was measured. Brittle fracture was occurred from the fracture surface of angular pin, therefore, impact toughness value was evaluated by V-notch Charpy impact test. It was confirmed that the impact absorption energy was high when was tempered at a high temperature for a long time, and the toughness was slightly increased. Also, 2-parameter Weibull statistical analysis was investigated in order to evaluate the reliability of the measured micro Vickers hardness values and absorbed energy. The micro Vickers hardness and absorbed energy well followed a two-parameter Weibull probability distribution, respectively. The reverse design against angular pin was proposed as possible by using test results.

• Journal of Aerospace System Engineering
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• v.7 no.2
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• pp.55-59
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• 2013

Before avionics equipment are installed in aircraft, several environmental tests such as temperature, vibration, lightning, fire etc. must be conducted. One of the environmental tests is to substantiate protection designs of lightning indirect effect. It can be showed through RTCA DO-160G, section22 "Lightning Induced Transient Susceptibility" test. An additional test of aircraft level is required as well after installation of avionics equipment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.603-607
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• 2002

Cavity pressure is a factor of what is occurring inside the mold and is used as one of the process parameters that control the overall injection molding cycle. The insight of cavity pressure is able to predict part quality and optimum process condition. In this paper, it is adapted ejector pin sensor to measure the cavity pressure and investigates the flow balance and the cavity pressure according to different runner thickness for adjusting the flow balance. Flow balance is very important to have not the poor results such as flash and warpage in the family mold. This paper predicted flow balance and cavity pressure using CAE analysis tool and compared with the test results. The results of analysis and test have a good agreement with the cavity pressure profile and flow pattern of the test.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.2
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• pp.277-289
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• 1996

The purpose of this study was to compare the amount of the vertical pin opening of dentures processed by the conventional compression method & the injection-processing method. The articulating ribbon and T-Scan system were used to determine the changes in tooth contacts and the correlation between the changes in tooth contacts and the amount of the vertical pin opening after processing was analyzed statistically. The obtained results were as follows. 1. The amounts of the vertical pin opening were 0.75mm, 0.31mm for conventional compression method and injection-pressing method, respectively. The difference between the two methods was highly significant on the basis of t test statistics(p<0.05). 2. The total number of contact points recorded by articulating ribbon after processing was decreased to 48%, 72%, of that before processing for conventional compression method and injection-pressing method, by T-Scan system, 39%, 53%, respectively. 3. The mean values for the number of contacts points per tooth recorded by articulating ribbon after processing were 1.6 for the second molar, 2.2 for the first moalr, 0.4 for the second premolar, 0.6 for the first premolar in conventional compression method, and 2, 3.2, 1.2, 0.8 in injection-pressing method. 4. The correlation between the reduction of contact points and the amount of the pin opening after processing was not significant. 5. The mean values for the number of contact points per tooth recorded by T-Scan system after processing were 1.25, 1.4, 0.7, and 0.55 at the second molar, the first molar, the second premolar, and the first premolar in conventional compression method, and 1.45, 2.1, 1.0, 0.75 in injection method, respectively. 6. The correlation between the number of contact points by using articulating ribbon and T-Scan system after processing was not significant in both methods.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.278-290
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• 1997

The purposes of this study were to evaluate and compare the pulpal anesthesia induced by an inferior alveolar nerve block and that by Gow-Gates technique, and to investigate the relationship between pulpal anesthesia and intraoral soft tissue responses. After one side of mandibule was anesthetized with inferior alveolar nerve block or Gow-Gates technique using 2 % lidocaine with 1 : 100,000 epinephrine in 19 volunteers of ages between 24 and 29 (16 males and 3 females, average age 25.9 yrs.), electric pulp tests were done on the canine teeth of the anesthetized side and contralateral one before, at 1 min, continued at every 5 minutes until 60 min, and every 10 minutes until 100 min after completion of local anesthetic injection. Degree of pulpal anesthesia was classified as anesthetic failure, possible anesthesia and complete anesthesia by the criteria based on the thresholds to electric pulp test of contralateral canine and the currents of the electric pulp tester. Subjective signs on the lower lip and tongue were checked and prick-pin tests were done on the buccal gingiva of the first molar, buccal and lingual gingiva of the canine tooth at 5, 10 and 20 min after the completion of anesthetic injection. Thresholds to electric pulp test, degree of pulpal anesthesia and relationship between the pulpal anesthesia and soft tissue responses were analyzed with SPSS, paired t-test, Wilcoxon matched-pairs signed-ranks test and correlation analysis. The results were as follows : No significant differences were found in the peak thresholds to electric pulp test, in the induction time to it and in the depth of pulpal anesthesia between inferior alveolar nerve block and Gow-Gates technique (p>0.05). There was no significant relationship between pulpal anesthesia and soft tissue responses in both inferior nerve block and Gow-Gates technique.

• Clinical Pain
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• v.19 no.2
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• pp.116-119
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• 2020

Cervical transforaminal epidural steroid injection (TFESI) is commonly performed to provide relief of pain caused by radiculopathy. Intra-arterial injection of particulate steroid or direct needle injury can lead to spinal artery embolism or thrombosis. Also there is a possibility of vascular spasm. To our knowledge, this is the first reported case of spinal cord infarction that occurred after TFESI with non-particulate steroid in Korea. A 47-year-old female patient underwent C7 TFESI at local pain clinic. Injected materials were dexamethasone and mepivacaine. Right after the intervention, she felt muscle weakness and decreased sensation. On physical examination, she had decreased sensation from C4 to T2 dermatome in light touch and pin-prick test. Proprioception and vibration were intact. The motor grades of upper extremities were grade 1. Cervical and thoracic spine MRI was checked. Diffusion-weighted image and apparent diffusion coefficient image showed long extension of spinal cord infarction from C2 to T1 level.

• The Korean Journal of Pain
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• v.1 no.2
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• pp.154-163
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• 1988

In 1983, Sten H$\ddot{a}$kanson first reported the clinical safety and efficacy of retrogasserian glycerol injection as a treatment of typical trigeminal neuralgia in 96 of 100 patients during a follow-up period of 1~6 years. Since September 1987, we have injected sterile pure glycerol into the trigeminal cistern using an anterior percutaneous approach via the foramen ovale (H$\ddot{a}$rtel route) for treatment of tic douloureux in 12 patients who were suffering from attacks pain of following discontinuation of carbamazepine. The results were as follows; 1) Eight patients were completely free from pain attacks with a single dose of glycerol (0.4 ml). The remaining four patients needed a second dose (0.4 ml) several days later following the single dose. The degree of patient's subjective satisfaction by those injections was very good in 11 and fair in one. 2) During the follow-up period (1~13 months), persistent sensory deficit as determined by the pin prick test, appeared to be mild in 10 and moderate in one patient. There was no sensory deficit in one patient. further attacks of pain from those injections were still noted. 3) As a transient complication, there was headache in all patient, facial hematoma in 4, nausea and vomiting in two each, and vertigo and herpes simplex in one each. In conclusion, we confirmed that the above glycerol injections into the trigeminal cistern were clinically very effective as a treatment of tic douloureux even though the follow-up period was short.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.445-454
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• 2014

In this paper, we introduce measures designed content for RTCA DO-160 F, Section 22 tests performed to verify the effects of indirect lightning and testing process of the test was carried out in the multi-purpose display certification process. This is referred to as indirect effects of lightning capability of an aircraft having electrical electronic equipment failure or damage to bring lightning induced voltages. In order to protect the avionics from lightning indirect effects of these aircraft are analyzing the effects of lightning strikes on aircraft and aircraft systems and interior design needs protection against the threat on their part. In this paper, we introduce RTCA DO-160 F, component selection process according to Section 22 category selection method and the selected level for determining the level of such measures for protection against lightning of multipurpose display for this aircraft. It also introduces the actual test process to confirm that the designed effectiveness of the selected part. We expect a good example of the lightning planned for future development of measures designed avionics through each step of the process introduced this.

• Journal of Broadcast Engineering
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• v.6 no.1
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• pp.82-97
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• 2001

In this paper, we describe a software implementation of a digital TV stream analyzer that can be used for analyzing and verifying digital TV bitstreams on personal computes. It accepts as input MPEG-2 transport streams (TS's) already stored on hard disks and doesn't require any special hardware. After classifying TS packets into program specific information(PSI) TS section auido, video, program clock reference (PCR) private data and null packets, it displays their contents through a graphic user interface along with the syntax elements of the TS header. Also it displays the decoded I frame nearest in time axis the TS packet currently shown This feature helps pin pointing the specific location of problematic parts in bitstreams. The bitsteam analyzer provides the compliance test of MPEG-2 Systems standard and the data injection functionality with which one can easily insert additional data to existing MPEG-2 bitstreams. Using the resulting system one can produce at low test streams for interactive broadcasting and data broadcasting for laboratory use.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.395-402
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• 2015

This paper introduces the design details and test procedures of the lightning induced transient protection device for protecting the damage caused by indirect lightning strike on the computer mounted on the aircraft. Lightning induced surge voltage is bring a malfunction or damage to the aircraft electrical and electronic equipment, that is referred to indirect effects of lightning. In order to protect the electronic equipment on aircraft from the indirect effects of lightning, that is achieved by analyzing the effect on aircraft from lightning and protect design for each devices. In this paper, we introduce an indirect lightning strike level decisions, the protection circuit design method according to the chosen level through the RTCA DO-160G Section 22 category analysis and selection was performed in order to protect the damage caused by indirect lightning strikes in the protected equipment. In addition, we show the indirect lightning effects verification test performed to validate the designed protection circuits.