• Physical Therapy Korea
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• v.15 no.4
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• pp.34-42
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• 2008

This study aimed to examine whether McConnell taping for deltoid inhibition affects the Electromyographic (EMG) activity of shoulder girdle muscles during arm elevation. Ten young healthy men were randomly assigned to an experimental and control groups of five men each. For the experimental group, we performed taping for deltoid inhibition on the skin over anterior and posterior deltoids with non-elastic specific tape, and sham-taping with non-elastic under-tape for the control group. Surface EMG measurements were performed three times (before, during and after the tapings) at upper and lower trapezius, mid-deltoid, and serratus anterior muscles while elevating dominant aim with loading and unloading conditions. In deltoid inhibition taping group, there were significant differences in EMG activity of mid-deltoid (p<.05) and serratus anterior (p<.05) muscles during arm elevation with loading. During arm elevation without loading, the EMG activity was significantly decreased for MD in the McConnell taping group (p<.05). The findings indicate that deltoid inhibition taping can modify the activation patterns in shoulder girdle muscles as well as in deltoid muscle. in clinical setting. it may be effectively used for the management of patients with shoulder dysfunction.

• Journal of Korea Technology Innovation Society
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• v.15 no.3
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• pp.500-532
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• 2012

This study analyzed the technology innovation strategies of knowledge-based companies in the semiconductor IP industry. The theoretical approaches of this study are to i) the creation, protection and utilization of knowledge and innovation, ii) value creation from innovation, iii) modularity, timing of market entry, and the emergence and competition of standard (dominant design). Based on the theoretical analysis, I presented exploratory research hypotheses. Ultimately, this study examined the proposed hypotheses by conducting case studies on the technology innovation strategy of two leading knowledge-based companies in the semiconductor IP industry: ARM and INTEL. First, knowledge-based companies entering in the early stage of the technology cycle select the vertically-integrated technology strategy because of lower access to complementary knowledge assets, and maintain the vertically-integrated technology strategy despite the environmental change-driven differentiation of industry's value chain. Second, knowledge-based companies entering in the later stage of the technology cycle prefer the contract-based technology strategy because of its increased accessibility to complementary knowledge assets, and choose a different path of innovation strategies depending on whether their asset has the feature of discontinuity or not.

• Physical Therapy Korea
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• v.19 no.2
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• pp.12-19
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• 2012

The purpose of this study was to assess the influence of scapular alignment on the electromyographic (EMG) activity of the trapezius in people with a short pectoralis minor muscle. For the study, we recruited 15 volunteers who had positive results for short on a pectoralis minor muscle length test. We measured the EMG activity of the upper, middle and lower trapezius muscles. The participants lifted their dominant arm to ear level with the thumb up toward the ceiling in the prone position on a table with the shoulder at a flexion angle of 180 degrees and a horizontal abduction angle of 120 degrees. Scapula was manually aligned by an experienced physical therapist prior to arm lift for the scapular alignment condition. A paired t-test was used to compare the effects of scapular alignment on the EMG activity of the trapezius muscles. The EMG activity of the lower trapezius muscle was significantly increased during the test with the scapular alignment compared to that without scapular alignment (p<.05), while the upper trapezius and middle trapezius exhibited no significant difference between the two conditions (p>.05). The findings of this study suggest that a scapular alignment may alter the recruitment of the lower trapezius muscle during arm lifting in the prone position in people with a short pectoralis minor muscle.

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.155-161
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• 2021

Objective: There is a lack of studies using the 3D-2D image registration techniques on the mechanism of a shoulder injury for ice hockey players. This study aimed to analyze in vivo 3D glenohumeral joint arthrokinematics in collegiate ice hockey athletes and compare shoulder scaption with or without a hockey stick using the 3D-2D image registration technique. Method: We recruited 12 male elite ice hockey players (age, 19.88 ± 0.65 years). For arthrokinematic analysis of the common shoulder abduction movements of the injury pathogenesis of ice hockey players, participants abducted their dominant arm along the scapular plane and then grabbed a stick using the same motion under C-arm fluoroscopy with 16 frames per second. Computed tomography (CT) scans of the shoulder complex were obtained with a 0.6-mm slice pitch. Data from the humerus translation distances, scapula upward rotation, anterior-posterior tilt, internal to external rotation angles, and scapulohumeral rhythm (SHR) ratio on glenohumeral (GH) joint kinematics were outputted using a MATLAB customized code. Results: The humeral translation in the stick hand compared to the bare hand moved more anterior and more superior until the abduction angle reached 40°. When the GH joint in the stick hand was at the maximal abduction of the scapula, the scapula was externally rotated 2~5° relative to 0°. The SHR ratio relative to the abduction along the scapular plane at 40° indicated a statistically significant difference between the two groups (p < 0.05). Conclusion: With arm loading with the stick, the humeral and scapular kinematics showed a significant correlation in the initial section of the SHR. Although these correlations might be difficult in clinical settings, ice hockey athletes can lead to the movement difference of the scapulohumeral joints with inherent instability.

• Composites Research
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• v.35 no.5
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• pp.303-308
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• 2022

PIC (Piecewise Integrated Composite) is a new concept for designing a composite structure with mosaically assigning various types of stacking sequences in order to improve mechanical properties of laminated composites. Also, machine learning is a sub-category of artificial intelligence, that refers to the process by which computers develop the ability to continuously learn from and make predictions based on data, then make adjustments without further programming. In the present study, the tapered box beam type PIC robot arm for carrying and transferring wide and thin LCD display was designed based on the machine learning in order to increase structural stiffness. Essential training data were collected from the reference elements, which were intentionally designated elements among finite element models, during preliminary FE analysis. Additionally, triaxiality values for each finite element were obtained for judging the dominant external loading type, such as tensile, compressive or shear. Training and evaluating machine learning model were conducted using the training data and loading types of elements were predicted in case the level accuracy was fulfilled. Three types of stacking sequences, which were to be known as robust toward specific loading types, were mosaically assigned to the PIC robot arm. Henceforth, the bending type FE analysis was carried out and its result claimed that the PIC robot arm showed increased stiffness compared to conventional uni-stacking sequence type composite robot arm.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.112-117
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• 2009

The new suspension, called ISU(In-arm suspension system) was developed for Infantry Fighting Vehicle. During vehicle field test, early failure of ISU's sealing system was occurred after driving the paved road. From the failure analysis, ISU's displacement data was obtained. In analysis of PSD data, track induced vibration which has high frequency and small amplitude characteristics, was dominant. Such track vibration would result in early seal failure because of friction increase and lack of lubrication. To simulate track vibration environment in laboratory, seals were tested under the condition of 20Hz, ${\pm}1$, ${\pm}2mm$ amplitude. The same type of seal failure occurred in vehicle test, was reproduced in the lab test under ${\pm}1mm$ amplitude. From the test results, the durability of improved seal was increased by 2.5 times compared with the previous one.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.321-324
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• 2003

This paper presents a novel system that analyzes and recognizes a gait based on shape context on silhouette images. The main functions of the system consist of three steps: First, the system extracts the silhouette images from galt image sequence by performing a simple pre-processing and acquires the AGM(Averaged Gait Map) by averaging them. Next. it computes the cross-correlation between the AGMs. Finally, it classifies the AGMs based on the cross-correlation using nearest neighborhood classification. The proposed system uses two cues to classify a gait: One corresponds to biometric shape cue such as body height width. and body-part proportions. The other corresponds to gait cue such as stride length and amount of arm swing. Perceptionally, the biometric cues are sailent on the double support (both legs spread and touching the ground) while the gait cues on the midstance. Through a variety of experiments, it is proved that the property of a gait is mainly influenced by gait cues than biometric cues.

• Archives of Reconstructive Microsurgery
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• v.4 no.1
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• pp.52-57
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• 1995

The authors have reviewed 19 patients of brachial plexus injury who treated by operative methods at Department of Orthopedic Surgery, Korea University Hospital during the period from January 1989 to February 1994. All of these patients were followed up more than one year and following results were obtained. 1. The whole arm type injury was most common(7 of 19 patient) and supraclavicular lesion(15 of 19 patient) was more dominant than infraclavicular lesion(4 of 19 patients). 2. The neurorrhaphy, nurolysis, nerve grafting, and neurotization were performed for the primary neural surgery and secondary reconstructive procedure consist of musculotendinous transfer and free muscle transfer with neurotization. 3. The followed up period was from one year to four years and six months, average being two years and five months. 4. We have obtained satisfactory results in 12 patients among 19 patients.

• Wind and Structures
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• v.16 no.3
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• pp.225-240
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• 2013

The wind-induced vibrations of the mast arm of cantilever traffic signal structures can lead to the fatigue failure of these structures. Wind tunnel tests were conducted on an aeroelastic model of this type of structure. Results of these experiments indicated that when the signals have backplates, vortex shedding causes large-amplitude vibrations that could lead to fatigue failure. Vibrations caused by galloping were only observed for one particular angle of attack with the signals having backplates. No evidence for galloping, previously thought to be the dominant cause of fatigue failures in these structures, was observed.

• Clinics in Shoulder and Elbow
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• v.7 no.1
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• pp.5-9
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• 2004

Purpose: To identify associated findings in glenohumeral joint in rotator cuff tear and evaluate its clinical significance, we examined minor and major changes during arthroscopic or mini open repair. Materials & Methods: We reviewed 66 patients of rotator cuff tear treated from March, 2001 to January, 2004. Of 38 cases of small to medium tear, average age was 53 years old and involved in dominant arm in 27 cases. Of 28 cases of large to massive tear, average age was 58 years old and involved in dominant arm in 26 cases. Minor and major associated changes of the glenohumeral joint were evaluated in the tendon of biceps long head, biceps pulley, cartilage of the glenoid and humeral head, labrum and synovium. Results: Minor changes in biceps tendon were in 35% of cases, biceps pulley in 18%, cartilage of humeral head in 27%, cartilage of glenoid in 18%, labrum in 38%, and synovium in 42%. Major changes in biceps tendon were in 6% of cases, biceps pulley in 35%, arthritis of humeral head in 3%, arthritis of glenoid in 2%, labrum in 6%, and synovium in 21 %. Major changes in biceps tendon were 5% in Group I and 7% in Group Ⅱ(p>0.05) and in biceps pulley, 18% and 57% in each (P<0.05). Minor changes of arthritis were prevalent in glenoid cartilage and major changes were more prevalent in humeral head. There were no differences in minor changes of labrum and synovium, but major changes were more prevalent in Group Ⅱ. Conclusion: The prevalence of intraarticular associated changes of rotator cuff tear were 63% in synovium, 54% in labrum, 53% in biceps pulley, 41% in biceps tendon, 30% in humeral head and 20% in glenoid cartilage in order. Major changes of biceps pulley, humeral head, labrum and synovium were more prevalent in Group Ⅱ.