• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.1-8
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• 2004

In this paper we present the effects that valve train design parameters and operating conditions have on the valve rotation properties of a diesel engine. Rotation of intake and exhaust valves are very closely related to the long term durability of diesel engines. of the valves do not rotate even at a rated engine speed, it causes the uneven wear of the valve seat and valve head contact area, which eventually shortens the engine life. Because the rated speed of a diesel engine is relatively lower than that of a gasoline engine, the operating condition of a diesel engine produces tough environment for valve rotation. Therefore, the valve rotation is an important problem which should be solved in the early stage of engine development. In this study, we developed a new technique to measure the valve rotation and shaking motion simultaneously using three proximity sensors. Valve train rotating properties of a diesel engine were measured under various engine operating conditions.

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.769-776
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• 2001

This study were to review of muscle imbalance of head, cervical and shoulder region. Head, cervical and shoulder region is a complicated mechanical unit. interconnected by numerous soft tissue links. These links, or articulation are functionaly and reflexly interdependent on one another. The line of gravity falls anterior to the transverse axis of rotation for flexion and extension of the head and creates a flexion moment. which tends to tut the head forward, is counteracted by tension in the tectorial membrane, and ligamentum nuchae, and by activity of the neck extensors. Therefore, the flexion moment equilibrate with the extension moment. Changing of the equilibrium will make mid cervical straight. It will make forward head posture(FHP) also. FHP makes imbalance of suboccipital muscles, suprahyoid muscles and infrahyoid muscles. It has some relationship with temporomandibular joint, spine and equilibrium of pelvis.

• 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.

• Journal of Korean Physical Therapy Science
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• v.13 no.1
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• pp.21-27
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• 2006

The purpose of this study was to identify the above mentioned therapy on the reduction of functional leg length inequality, by the manipulation(Thonpson technique). In 8 patients who have been chronically ill with low back pain and functional leg length inequality, for past 12 weeks, we analyzed and observed the progress of symptom and sign on pelvis(femur head line level, ilium length, ilium rotation), using by X-ray. The results after 12 week treatment, compared with before treatment, were as follows : 1. The improved in femur head line in the manipulation after 12 week treatment was very significant(p<.01) 2. The improved in ilium length in the manipulation after 12 week treatment was very significant(p<.01) 3. The improved in ilium rotation in the manipulation after 12 week treatment was significant(p<.05).

• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.190-201
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• 2017

This paper proposes how to solve a problem of FDM 3D printer's irregular output when changing volume of extrusion, adjusting movement speed of the printer's head and a way to fill new inner part. Existing slicers adjust directly to change the rotation speed of the stepper. In this method, the change of the extrusion area is delayed due to the gap between the stepper and the nozzle, so that precise control is difficult. We control the extrusion area adjusting the moving speed of the print head and making constantly the rotation speed of the stepper. Thus, the output time can be shortened by generating an efficient path having a short travel distance. For evaluation, we applied our method to lithophanes with detailed variation. Comparing existing methods, our method reduced output time at least 30%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3820-3841
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• 2018

Most of the accidents occur due to drowsiness while driving, avoiding road signs and due to driver's distraction. Driver's distraction depends on various factors which include talking with passengers while driving, mood disorder, nervousness, anger, over-excitement, anxiety, loud music, illness, fatigue and different driver's head rotations due to change in yaw, pitch and roll angle. The contribution of this paper is two-fold. Firstly, a data set is generated for conducting different experiments on driver's distraction. Secondly, novel approaches are presented that use features based on facial points; especially the features computed using motion vectors and interpolation to detect a special type of driver's distraction, i.e., driver's head rotation due to change in yaw angle. These facial points are detected by Active Shape Model (ASM) and Boosted Regression with Markov Networks (BoRMaN). Various types of classifiers are trained and tested on different frames to decide about a driver's distraction. These approaches are also scale invariant. The results show that the approach that uses the novel ideas of motion vectors and interpolation outperforms other approaches in detection of driver's head rotation. We are able to achieve a percentage accuracy of 98.45 using Neural Network.

• Transactions of the Society of Information Storage Systems
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• v.7 no.1
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• pp.36-41
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• 2011

The micro laser module was designed and prepared to deliver the light to the HAMR head. It consists of laser diode, photo diode and actuator to realize stable light delivery even though the head is fluctuated during the disk rotation. The optical evaluation was carried out with the actual distance between the light source and HAMR head with a range of reflectivity and it was found that the incident angle could be controlled within ${\pm}0.125^{\circ}$ to maintain same intensity into the HAMR head. It was also confirmed that the designed micro laser module is thermally stable without any severe effect on the magnetic head.

• Journal of Korean Physical Therapy Science
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• v.19 no.2
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• pp.17-24
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• 2012

Purpose : The purpose of this study was to show the effect of postural training through action observation (AO) on craniovertebral angle (CVA) and cranial rotation angle (CRA) of forward head posture (FHP). Methods : From 16 subjects of having the FHP who consist of postural training through the AO (n = 8) and control group (n = 8) were training to three times per one week during three weeks. FHP measurements for pre and post the intervention use to Wiz-pacs(Wiz-Picture Achiving Communication System) from X-ray change of CVA and CRA. Results : The study for the change within the group pre and post the intervention, CVA and CRA were found the significant differences only in the postural training group through the AO (p<.05). In the comparison of the rates of change between the groups pre and post the intervention CVA and CRA all showed the significant differences (p<.05), and in the comparison of the rates of average change of individual variables in each groups, the postural training group through the AO showed more change rates. Conclusion : The study suggests that when people with FHP received the postural training, the postural training through the AO resulted in more change into the correct postures.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.8
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• pp.11-23
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• 2000

Head-eye calibration is a process for estimating the unknown orientation and position of a camera with respect to a mobile platform, such as a robot wrist. We present a new head-eye calibration technique which can be applied for platforms with rather limited motion capability In particular, the proposed calibration technique can be applied to find the relative orientation of a camera mounted on a linear translation platform which does not have rotation capability. The algorithm find the rotation using a calibration data obtained from pure Translation of a camera along two different axes We have derived a calibration algorithm exploiting the rectification technique in such a way that the rectified images should satisfy the epipolar constraint. We present the calibration procedure for both the rotation and the translation components of a camera relative to the platform coordinates. The efficacy of the algorithm is demonstrated through simulations and real experiments.

• Clinics in Shoulder and Elbow
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• v.22 no.4
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• pp.216-219
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• 2019

Background: Progression of the tear size and erosion of the greater tuberosity (femoralization) in the supraspinatus tear makes it difficult to repair or increases the risk of a re-tear. This study examined the proximal articular surface and greater tuberosity of the humeral head in plain radiography. Methods: Two-hundred forty-seven cases, whose anteroposterior (AP) radiographs were taken correctly, were included from 288 cases, in whom the status of the supraspinatus had been confirmed by surgery. After downloading the plain AP radiograph as DICOM, the radius of the circle apposed at the superior half of the articular surface of the head, and the distance between the circle and the farthest point of the greater tuberosity ('height' of the greater tuberosity) were calculated using the software (TechHime, Korea). MRI checked the number of torn tendons and degree of muscular atrophy. Results: The following were encountered: 93 intact supraspinatus, 50 partial-thickness tears, and 104 full-thickness tears. In the analysis using the 93 intact cases, the average radius of the rotation center was 25.3 mm in male and 22.3 mm in female. The average height of the greater tuberosity from the circle with the same rotation center was 4.3 mm in male and 4.2 mm in female with no statistical significance. The correlation between the reparability of supraspinatus and height of the greater tuberosity, fatty infiltration, and muscular atrophy was confirmed. Conclusions: The height of the greater tuberosity from the circle with the same rotation center was 4.3 mm in male and 4.2 mm in female. This height was strongly correlated with muscular atrophy and fatty infiltration of the supraspinatus tendon.