• Journal of Ocean Engineering and Technology
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• v.31 no.4
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• pp.281-287
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• 2017

In the case of fixed offshore wind turbines, scouring phenomena have been reported around sub-structures as a result of currents, which seriously damage the structural stability. A parametric study of the various sub-structures of a fixed offshore wind turbine was performed to investigate their effects on the scouring phenomena. For a suction bucket foundation and monopile, the effects of the stick-up heights and water depth were studied, respectively. The open source libraries, called OpenFOAM, were used to simulate a violent flow around a foundation. The numerical methods were selected based on a two-dimensional analysis of a suction bucket. Based on the results for various stick-up heights, a larger scouring region was observed with an increase in the stick-up height because of the down-wash flow around a foundation. Based on the results for various monopile water depths, the water depth had an insignificant effect on the scouring.

• Journal of Veterinary Clinics
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• v.39 no.4
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• pp.173-176
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• 2022

Intravenous catheterization is a common procedure in human and veterinary medicine. Occasionally, a catheter might break within the blood vessel, and the fragment may cause embolization, infections, or other severe complications, and therefore must be removed promptly. For a successful and low-risk removal, the fragment should be localized accurately; however, ultrasound may be challenging to perform on small dogs due to inadequate probes. We report the case of a 2-year-old, 2.6 kg, intact female toy poodle that presented to the veterinary medical center owing to a recent onion intake; the owner requested to induce emesis. A 24 gauge peripheral intravenous catheter was inserted into the cephalic vein prior to the emetic injection. When the clinician removed the catheter, a device breakage was observed. A tourniquet was applied immediately proximal to the elbow. Ultrasonography was performed with a high-frequency small-footprint linear array transducer, also called a hockey-stick probe, to localize the fragment. An additional ultrasound was performed before surgery to confirm the location of the catheter piece, which migrated 5 cm proximally. Afterward, a surgical intervention allowed us to retrieve the fragment. This report highlights the effectiveness of a hockey-stick probe to determine the location of a catheter fragment in small breed dogs.

• Journal of the Korean Society of Costume
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• v.60 no.2
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• pp.68-80
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• 2010

In order to get the information needed for the preservation and application of Korean traditional dyeing techniques to modern textiles products, the present study analyzed the color and color differences of dyed goods according to the contents of fabrics and the traditional techniques of dyeing the Buddhist priests' robes. A spectrophotometer was used to measure the differences in achromatic color according to dyeing techniques, dyestuff, kinds of dyed fabrics, and after-treatment methods. Through experiments based on the traditional dyeing techniques used by Korean Buddhist priests, a total of 144 pieces of dyed fabrics were made and all the colors of those 144 pieces were analyzed. Among three dyeing techniques tested; (1) dyeing with a dye-bath made of ink stick that was ground down with water, (2) dyeing with a dye-bath made by shaking a bag containing ink powder in water, and (3) dyeing with a dye-bath made by rubbing a boiled ink stick on a fabric, dyeing with a dye-bath made of ink stick that was ground down with water was shown to be the best technique in terms of coloring. For fabrics, ramie was the best of all three techniques in terms of making achromatic color. Starching and rubbing was the most effective after-treatment method used on both fabrics dyed with a grounded ink stick and on fabrics dyed by rubbing a boiled ink stick on them. As a whole, yangyeonmook, made from minerals' soot, is better than songyeonmook, which is made by burning old pine trees or yooyeonmook, which is made by burning oils from seeds. Therefore, yangyeonmook could help to preserve and utilize the traditional dyeing techniques of Korea in a practical way in modern life.

• 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.

• The Journal of the Acoustical Society of Korea
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• v.43 no.3
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• pp.270-276
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• 2024

In this study, we analyzed the stick slip characteristics through friction experiments on materials used in mechanical and electronic products, and propose improvements to reduce abnormal noise generated inside refrigerators. To analyze the stick slip phenomenon of the materials, we fabricated a friction testing device and conducted friction experiments. Additionally, we measured the vibration and noise levels of internal components to analyze the occurrence and location of abnormal noise inside the refrigerator. By comparing the results of the refrigerator's phenomenon analysis and friction experiment, we confirm that the abnormal noise occurring inside the refrigerator is caused by the stick slip phenomenon of internal components. Finally, to propose improvements for abnormal noise reduction, we performed friction experiments using the Taguchi method and validated the performance of the proposed improvements by applying them to refrigerators.

• Fibers and Polymers
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• v.4 no.2
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• pp.54-58
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• 2003

Previous research on healthcare workers’ protection has concentrated on liquid barrier protection by providing impermeable personal articles such as latex gloves. This property is of high importance but since most blood-borne pathogen transmissions in the healthcare industry are caused by needle-stick injuries, protection from sharp invasive instruments should also be of high concern. And since latex and alike provide no protection against needle-stick injuries, new protective systems need to be developed and evaluated. This part of the study provides a review regarding the current practice of protection and the serious problems that arise from needle-flick injuries. Additionally, the development of new protective system is described. In part II of the study, evaluation of the new system will be provided.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.690-693
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• 2006

As the silence of vehicle is more important, noise reduction of tire is more required. Noise of tire is divided into structure home noise and air borne noise. Tire tread has the property such as Hardness. Pattern Noise is caused by changing of tread hardness. This property has influence on the mechanisms which are Block Impact & Stick-slip sound. In the study, we found that the effect of Hardness is related to more Stick-Slip than Impact.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.4
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• pp.64-71
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• 2001

In general, precise linear actuators using piezoelectric element are driven by friction force. Exact understanding of friction plays an important role in analysis and control of a motor. In this research, we designed a precise linear actuator using piezoelectric elements and observed its dynamic characteristics. By varying phase angle difference and amplitudes of the sinusoidal waves that are driving inputs, we can know that it is possible to control moving direction and distance of the slider. As preload is increased, its moving distance is decreased. And also, we have modeled a precise linear actuator using stick slip friction models such as classical, Karnopp. and reset integrator. Finally, by comparing the results of simulation and experiment, it was verified that the model is well designed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.3
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• pp.61-67
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• 2017

The Nose Landing Gear(NLG) of Rotary Wing Aircraft is an essential equipment in Landing System for pilot to perform a flight mission. It supports the fuselage at ground and absorbs the impact from the ground when landing, thereby, these functions sustain operational capability for pilot and crew. However, the A aircraft caused stick-slip behavior when it was stationed on the ground. Therefore, this paper summarizes pilot comment in operation which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.5
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• pp.97-106
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• 1990

A method of weight evaluation of the load-bearing structural elements of cars is presented and the weight ratio of the analysis model is investigated. Replacing the materials of floor elements of the car into the high-strength steel, a considerable weight-reduction of the model has been obtained. The 1500cc model is selected for the present study and the stick model analysis is employed for the structural analysis. The torsional stiffness of the weight-reduced model is also evaluated and it is shown it has a reasonable rigidity. The ratio of the weight of the load-bearing structural elements to the unladen vehicle weight of cars is about 0.12for the 1500cc model and the weight-reduction of this study can be obtained around 17% of the weight of the load-bearing structural elements.