• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.109-117
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• 2018

Objective: To compare head and hand movement patterns during squash forehand motions between experts and less-skilled squash players. Method: Four experts and four less-skilled squash players participated in this study. They performed squash forehand swings and a VICON motion analysis system was used to obtain displacement and velocity data of the head and right hand during the movement. Mann-Whitney U-tests were performed to compare head and hand range of motion and peak velocity, and cross-correlation was performed to analyze the head-hand coordination pattern between groups in three movement directions. Results: In terms of head and hand kinematic data, experts had greater head range of motion during down swings than less-skilled squash players. Experts seemed to reach peak hand velocity at impact by reaching peak head velocity followed by hand peak velocity within a given temporal sequence. In terms of head-hand coordination patterns, both groups revealed high positive correlations in the medial-lateral direction, indicating a dominant allocentric coordination pattern. However, experts had uncoupled coordination patterns in the vertical direction and less-skilled squash players had high positive correlations. These results indicate that the head-hand movement pattern likely an important factor squash forehand movement. Conclusion: Analysis of head and hand movement patterns could be a key variable in squash training to reach expert-level performance.

• PNF and Movement
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• v.3 no.1
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• pp.27-34
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• 2005

Objective : The purpose of this study was conducted to find correct head and neck patterns, manual contact. verbal commands with proprioceptive neuromuscular facilitation(PNF). Method : This is a literature study with books, seminar note and book for PNF international course. Result : Keep the information of the biomechanics and neural science in head and neck patterns and emphasize that manual contact, verbal commands and visual stimulus. Manual contacting for movement guide and stability of the $C_0/C_1$ verbal command and visual stimulus for correcting of the $C_0/C_1$ movements. Conclusion : In reminder for PNF learning, begin with head and neck and upper trunk patterns. In that time, Knott and Voss(1968) had not enough information about biomechanic movement components and neural science movement components. But Knott and Voss(1968) emphasized that head and neck patterns relate with trunk, upper extremities and lower extremities directly. Alar ligaments are relaxed with the head in neutral and taut in flexion. Axial rotation of the head and neck tightens both alar ligaments. The right upper and left lower portions of the alar ligament limit left lateral flexion of the head and neck. Therefore, head and neck patterns has to be modify. When head moving, eye and vestibular stimulus will be change. During head and neck patterns, must be consider about stimulus of eye system and vestibular system also.

• Korean Journal of Head & Neck Oncology
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• v.18 no.1
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• pp.46-49
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• 2002

Background: Free flaps have become a very important role in the ablative head and neck surgery with functional preservation of defect sites. The forearm free flap has many advantage of lack of bulk, ease of dissection, vascularity, and malleability. Patients and Methods: A review of 51 radial forearm free flaps performed between may 1990 and feburary 2001 at the Korea University was undertaken to determine outcome. Patient age ranged 27 to 72 years (mean 56). There were 44 men and 7 women. The most prevalent neoplasm was squamous cell carcinoma. Results: The tans verse cervical artery and the external jugular vein were the most frequent receipient sites for microvascular anastomosis. Total flap loss occurred in 2 cases (4%) and other complications were seen in 42%. Fifteen patients received preoperative irradiation and the complication was higher than non-irradiation patients, but statistically not significant. Conclusion: The radial forearm free flap offers a variety of reconstructive options for head and neck. Its low flap loss and complication rates offer the best choice for reconstruction of defect of head and neck malignancy.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.8 s.145
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• pp.1079-1091
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• 2005

The purpose of this study was to point out the unification of the size of swimming headgear by measuring detailed measurement of head ferm and systematizes the head form. A total of 300 male and female Korean adults aged from 18 years old to 35 years old were measured through the direct measurement method. This study attempted to identify the head form of male and female adults using measurement data and the head form was classified through factor analysis and cluster analysis. (1) Based on the fact that this study especially focuses on the size of swimming headgear, factor analysis was performed far both direct measurements with hair and without hair. For the measurements with hair, seven factors were extracted. They were head thickness factor, head width factor, width of side head factor, height of back head factor, length of front head factor, circumference of front head factor, thickness of front head factor and head height factor. They explained the $70.95\%$ of the measurements. (2) The cluster analysis was executed to classify the somatotype of the korean head form on the basis of similarity. According to the cluster analysis result, the measurements with hair categorized types, 'Woman's long-hair type', 'Small type', 'Long and flat type', 'Large type'. (3) Head circumference B and Left tragion - Vertex - Right tragion circumference which are generally length and width in choosing swimming headgear size were selected as measurement items far size of swimming headgear. Direct measurements and sizes of four swimming headgear with different materials taking into account their elongation rate were also compared.

• Proceedings of the KOR-BRONCHOESO Conference
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• 2009.04a
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• pp.36-37
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• 2009

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.193-198
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• 2000

Near-field recording NFR), advanced optical storage technology, relies on maintaining a small gap between the optical head and the media. This can be accomplished by utilizing the flying optical head concept as in the magnetic recording. In this research, slider/suspension system and plastic disk are tested for their head/disk interface performance. CSS tests are conducted to monitor the frictional and flying characteristics of sliders.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.179-183
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• 2006

Whiplash injuries of the neck are one of the most common injuries reported from automotive rear impacts. Whiplash injuries can be reduced by changing geometry of head restraint. Therefore, geometries of head restraint were evaluated according to the test procedures of the Korea New Car Assessment Program(KNCAP) to improve safety of head restraint. In this study, nine vehicle's head restraints were tested. As the test results, one head restraints is rated at "Marginal", three head restraints are rated at "Acceptable" level, and the last five head restraints are rated at "Good" level.

• 대한두경부종양학회:학술대회논문집
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• 2009.05a
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• pp.79-79
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• 2009

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.865-868
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• 2007

This research is the method that develops the efficient Source Head and the performance of Ion Implanter. Source Head is used during 20 days because Source Head's life time is different from the life time of most components. Components which is replaced to remake the Source Head is very expensive, and moreover, the above of 50% is used with one time. In this research, as we applied the influx method of the atom in aerial distributed method, obtained the effect which suppresses the portion which occurs with loss of thermion and is a possibility of lowering the pressure of the Arc. And then We it will be able to suppress be imbrued of the Chamber.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.51-58
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• 2017

This paper deals with the improvement of cluster head selection method in L-SEP for heterogeneous nodes among hierarchical routing protocols of wireless sensor network. Wireless sensor networks are classified into homogeneous and heterogeneous network. In heterogeneous network, SEP, L-SEP are mainly used because cluster head selection probability is different depending on node type. But, since protocol based on SEP has different cluster head selection probabilities depending on the node type, clusters that transmit data inefficiently can be formed. to improve this, it is necessary to select the cluster head that minimizes the transmission distance of member node and the cluster head. Therefore, we propose a protocol that improve the cluster head selection method.