• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.27-33
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• 2007

The purpose of this study was to investigate influence of wrist position on the electromyographic(EMG) activities of the flexor digitorum superficialis (FDS) and extensor digitorum (ED) during drilling and pinch grip. Eighteen healthy subjects had been recruited and each subject performed two tasks (drilling and pinch grip) at three different wrist positions ($30^{\circ}$ flexion, neutral, $30^{\circ}$ extension). The EMG amplitude of each muscle was normalized to the amplitude in the maximal voluntary contraction (MVC). Repeated one-way ANOVA was used to compare the differences of EMG across wrist positions. The FDS EMG activity in both drilling and pinch grip was lowest at $30^{\circ}$ wrist extension and the highest at $30^{\circ}$ wrist flexion. The ED EMG activity was lowest when the wrist was neutral in both tasks. From the results of this study, we can conclude that the desirable wrist positions for drilling and pinch grip tasks are slightly extended or neutral position. Therefore, flexed wrist position should be avoided to reduce the excessive work load on the finger muscles during the tasks.

• Tunnel and Underground Space
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• v.25 no.6
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• pp.534-542
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• 2015

Round trip activity occurs discretely due to the abrasion of drill bit in the deep drilling project. Round trip has great impact on the drilling performance because it takes more time to change a drill bit as the depth goes deeper. Therefore, a reliable prediction technology of the round trip should be secured for feasibility analysis and effective management of the drilling project. Lee et al. (2013) developed the TOSA (round trip occurrence simulation algorithm) which can analyze the depth and timing of round trip occurrence at each abrasion state of bit. However, TOSA has weakness that it takes long time for simulation because the number of simulation increase exponentially as increasing the number of simulation section. This study developed the TOSA based round trip performance prediction module using genetic algorithm for simulating in a short time and verified simulation results.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.73-82
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• 2017

This study is focused on concepts and types of drilling investigating the scope of activity and problems the application of marine environment and safety acts related to deep-sea drilling for the development of the continental shelf in Korea. For the systemic development of subsea mineral resources, this study suggest a legislative proposal for the establishment of a separate law based on the UK Offshore Installation (Safety Case) regulation and improvement of the marine environment management act, maritime safety act and oil & mining safety regulation. Specially, this study emphasized on the necessity of establishing education, training and evaluation system according to the international certification training for the domestic work force based on accident cases related to overseas offshore plants.

• Journal of the Korea Convergence Society
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• v.7 no.2
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• pp.77-84
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• 2016

This paper is aimed at finding whether foreign students' Korean speaking skills can be increased or not through memorizing whole Korean sentences and pair works. First, the advance studies on the effects of this teaching method were surveyed. Second, the activity of this study was mainly pair works with foreign students, so how to do this activity was described. This activity was intended to help each other with keeping study and correcting errors while drilling in class. Thanks to this convergence teaching approach the students' frequency of target language, the Korean language was dramatically increased, and their motivation and energy were brought from this activity. They have to do communications with each other because each pair was made of one Chinese and one Vietnamese. They have no choice but to use Korean in communication. Finally, the questionnaire and interviews also showed that almost all of the students were satisfied with this convergence teaching approach.

• Journal of the Korean Institute of Gas
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• v.21 no.2
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• pp.10-19
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• 2017

This paper presents the status and characteristics of oil and gas industry and the guideline for investment of producing asset or petroleum and natural gas rights(PNG rights) in Canada. The Western Canadian Sedimentary Basin(WSCB) consists of around 11 main formations, and petroleum has actively been produced at the Montney, Cardium, Viking and Bakken formation. However, the drilling activity declined to 1,917 in Q1, 2016 from 5,724 in Q1, 2014 and 3,365 in Q1, 2015 which dropped 67% and 43% respectively because of the low oil price since 2014. Also, the price of oil and gas asset decreased 34~47% on reserves and production base, and the PNG rights for development decreased 81~97% based on total bidding price, bidding area and unit bidding price. Therefore, it is very favorable environment for Korean companies entering into the Canadian petroleum business especially in PNG rights acquisition which needs smaller investment compare to asset acquisition and shows sharpest value depreciation.

• Journal of The Korean Association of Information Education
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• v.4 no.2
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• pp.159-168
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• 2001

A ultimate purpose of education is to develop their ability that learners is able to solve present or future immediate problem well. In order to, the educator checks question settlement conditions and leads steadily, the learner needs various data and information for question settlement, and needs communication with many various people. By the way, WEB becomes the source of various data and information that it is naccesary to solve problem for freedom navigation of internet, because accelerates interaction quality communication needed question settlement process, offers the best studying environment for problem solution drilling. A methodolagical tactics for accelerating learner's question solution activity is helped by small-group action drill. According to, this treatise develops system of question solution drilling with web for a basis by small group action drill, applies the fifth grade it experimentally.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.445-448
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• 2001

Noise radiated from pile driving operation is one of major sources of community noise pollution and thus its operation method is strictly restricted by regulations. Although the drilling method is now used been commonly used in urban areas because of its activity, the benefit of low noise decreases due to high working cost. In the present work, noise characteristics of pile driving operation are carried out. Based on the study result, a low-noise pile cap for driven piles is developed in order to satisfy both the noise level restriction and the economical efficiency. Effects of pile cap are investigated by a scale model experiment, which is focused on the variation of impact force and sound pressure level. The results show a good possibility of noise reduction by an appropriately designed pile cap.

• Journal of Korean Neurosurgical Society
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• v.54 no.4
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• pp.366-369
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• 2013

Lumbar microdiscectomy (MD) is the gold standard for treatment of lumbar disc herniation. Generally, the surgeon attempts to protect the facet joint in hopes of avoiding postoperative pain/instability and secondary degenerative arthropathy. We believe that preserving the facet joint is especially important in young patients, owing to their life expectancy and activity. However, preserving the facet joint is not easy during lumbar MD. We propose several technical tips (superolateral extension of conventional laminotomy, oblique drilling for laminotomy, and additional foraminotomy) for facet joint preservation during lumbar MD.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.235.1-235.1
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• 2003

With an aim of obtaining high efficacy in cartilage regeneration, implantable polymeric rods were fabricated. These rod-type matrices were anticipated to perform structural tissue supporting activity and enhance extracellular matrix (ECM) formation by releasing specific agent, DHEA-S, in controlled manner. It is expected that application for the drilling operation on the articular cartilage of OA patients as the implants may promote regeneration of their cartilage. Osteoarthritis (OA) is a degenerative joint disease characterized by progressive loss of articular cartilage, subchondral bone remodeling, spur formation, and synovial inflammation. (omitted)

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.76-80
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• 2004

Purpose: We assessed the results of open treatment of anterior impingement syndrome of the ankle in elite level soccer players and concomitant injuries were idenfied. Materials and Methods: We retrospectively reviewed twenty one elite level soccer players diagnosed with anterior impingement syndrome who underwent open debridement between January 1997 and January 2002. All were men and the mean age at the operation was 21 years (range 16 to 27). The mean follow-up duration was 31 months (13 to 71). Concomitant abnormalities were idenfied through physical examination, bone scan and MRI. On a preoperative lateral radiograph, patients were classified according to McDermott's stage. Anteromedial or anterolateral approach was used at the operation and osteophyte was removed with osteotome and rongeur. When chronic ankle instability was accompanying, we performed Modified Brostrom-Gould procedure and for osteochondral lesion, multiple drilling was applied. The Ogilvie-Harris scoring system was used as a clinical scale to evaluate pain, swelling, stiffness and limitation of activity. The results were scored as excellent (15 to 16 points), good (13 to 14) and otherwise unsatisfactory. The time to return to full activity including sports activity was determined. Results: Eighteen of twenty one patients had an excellent outcome. Three patients were graded unsatisfactory and two of them abandoned their career due to the persistence of residual pain. Concomitant abnormalities were found including twelve cases of chronic ankle instability, three cases of osteochondral lesion and two cases of flexor hallucis longus tendinitis. Conclusion: Open debridement was successfully applied to the elite level soccer player with anterior impingement syndrome of the ankle. Considerable coexistence of other abnormalities such as chronic ankle instability may encourage us to consider additional operative procedure.