• Clinics in Shoulder and Elbow
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• v.2 no.1
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• pp.35-40
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• 1999

Impingement syndrome is caused by a conflictual status between rotator cuff, subacromial bursa and anatomic and functional coracoacromial arch. The purpose of this study was to assessment the coracoacromial arch by MRI and to determine major factors among five components of coracoacromial arch. We analyzed forty-two cases of clinical impingement sign and test positive and postoperative confirmed diagnosed from March, 1991 to January, 1999. We evaluated acromial end abnormality according to the Bigliani acromial type and formation of osteophyte. Clavicular end abnormality classified flat, outward protrusion, inward protrusion to coracoacromial arch. Acromioclavicular joint abnormalities were advanced osteoarthritis and positive signal change. Coracoacromial ligament thickening was above 2 mm in oblique sagittal image. Coracoid process abnormality was inward protrusion to coracoacromial arch. All consecutive patients abnormalities were as follows: clavicular end osteophyte formation and inward protrusion to coracoacrmial arch were 30%, acromial end osteophyte formation was 28%, advanced acromioclavicular joint arthritis and osteophyte formation were 56%, coracoacromial ligament thickening was 24% and no coracoid process inward protrusion to coracoacromial arch. Impingement syndrome combined with rotator cuff tear group abnormalities were clavicular end(40%), acromial end(40%), acromioclavicular joint(20%), coracoacromialligament(20%) and coracoid process abnormality(0%) respectively. Only impingement syndrome group abnormalities were clavicular end(25%), acromial end(31%), acromioclavicular joint(62%), coracoacromial ligament(25%) and coracoid process(0%) respectively. Acromial type I(flat) were 6 cases, type II(curved) were 26 cases and type III(hooked) were 10 cases. We concluded that the most important contributing factors for impingement syndrome was acromial type and second was acromioclavicular joint arthritis and bony spur formation.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.2
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• pp.184-191
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• 2003

A parallel manipulator has high stiffness and all the joint errors on the device are not accumulated at the end -effector unlike a serial manipulator. These are the reasons why the parallel manipulator has been widely used in many fields of industry. In the parallel manipulator, it is very important to predict the exact pose of the end-effector when we want to control the end-effector motion. Installation errors have to be determined in order to predict and control the actual position and pose of the end-effector. This paper presents an algorithm to find the whole 36 joint error components with joint clearance errors and measurement errors considered, when a link length measurement sensor is used and data more than 36 times are acquired for 36 different configurations. A simulation test using this algorithm is performed with a Matlab program which uses the Levenberg-Marquardt method that is known to be efficient for non-linear optimization.

• Journal of the Korean Geotechnical Society
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• v.29 no.12
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• pp.105-111
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• 2013

The standard penetration test (SPT) has been widely used because of its usability, economy, and many correlations with soil properties among other factors. In SPT, hammer energy is an important factor to evaluate and calibrate N values. To measure hammer energy, an instrumented SPT rod was developed considering that stress waves transferring on rods during SPT driving are the same as stress waves transferring on piles due to pile driving. Using this idea, an instrumented SPT rod with a pile driving analyzer was applied as a pile capacity prediction tool in this study. In order to evaluate this method, SPT and dynamic cone tests with the instrumented SPT rod were conducted and also 2 pile load tests were performed on pre-bored steel pipe piles at the same test site. End bearings were predicted by CAPWAP analysis on force and velocity waves from dynamic cone penetration tests and SPT. Comparing these predicted end bearings with static pile load tests, a new prediction method of the end bearing capacity using the instrumented SPT rod was proposed.

• Steel and Composite Structures
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• v.52 no.1
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• pp.109-119
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• 2024

This study presents a replaceable reduced beam section (R-RBS) located at the column end in moment resisting frames (MRFs). An end of the R-RBS is connected to column by using end-plate moment connection and the other end of that is connected to main beam with beam splice connection. Therefore, the RBS that is expected to yield under an earthquake can be easily replaceable. Geometry of the RBS and the thickness of the beam splice connection are the prime variables of this study. A total of eight experimental test was carried out to examine the seismic performance of the proposed R-RBS with the connection details. The results obtained from experimental studies demonstrated that plate sizes of the beam splice connection significantly affect the seismic performance of RBSs used in MRFs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.890-893
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• 2000

In this paper, the test of machinability according to the cutting positions when the ball end milling of hemispheric workpiece is carried out to find the optimum cutting position of free form surface die. Tool runout, cutting force. and chip form are measured. The results show that the optimum cutting condition to get the constant feed per tooth is the inclined angle of 40 degree of workpiece.

• Journal of the Korea Furniture Society
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• v.11 no.1
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• pp.61-68
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• 2000

This study was carried out to investigate the effect of grain and veneer thickness on drying rate, required energy consumption, and drying defects such as checking, end waving, and burning during a far-infrared radiation drying process of decorative veneers of hard maple and beech. Most of the veneer could be dried from green to in-use moisture content within 30 to 360 seconds. The drying rates were significantly affected by veneer thickness, but there was little difference between edge-and flat-sliced veneers. The formation of checking during drying test was none or very slight. The percentages of the veneers defected by checks were higher in the flat-sliced veneers than in the edge-sliced veneers. The maximum end wavinesses in the flat-sliced veneers were almost 1.6 to 3 times larger than that in the edge-sliced veneers. All veneers were fee from burned marks during drying test.

• Structural Engineering and Mechanics
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• v.88 no.2
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• pp.189-200
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• 2023

Silicate glass is usually a brittle and plate-like material, and it is difficult to measure the elastic modulus by the traditional method. This paper develops a test method for the glass elastic modulus based on the fundamental frequency of the cantilever beam with an elastic support and a free end. The method installs the beam-type specimen on a semi-rigid support to form an elastic support-free end beam. The analytic solution of the stiffness coefficients of the elastic support is developed by the fundamental frequency of the two specimens with known elastic modulus. Then, the glass elastic modulus is measured by the fundamental frequency of the specimens. The method significantly improves the measurement accuracy and is suitable for the elastic modulus with the beam-type specimen whether the glass is homogeneous or not. Several tests on the elastic modulus measurement are conducted to demonstrate the reliability and validity of the test method.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.294-299
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• 2009

Micro end-milling has been becoming an important machining process to manufacture a number of small products such as micro-devices, bio-chips, micro-patterns and so on. Many related researches have given grand effects to micro end-milling phenomenon, for example, micro end-milling mechanism, cutting force modeling and machinability. This paper strongly concerned actual problem, micro tool deflection, which causes excessive machining errors on the workpiece. Machining error were predicted and measured through a series of test micro cutting and analysis of their SEM images and FEM analysis. Experiments are carried out to validate the approaches.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.422-427
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• 2004

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and to develop a software for design of end mill geometry.

• Annual Conference on Human and Language Technology
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• 2016.10a
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• pp.56-61
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• 2016

본 논문에서는 Sequence-to-sequence 모델을 생성요약의 방법으로 한국어 문서요약에 적용하였으며, copy mechanism과 input feeding을 적용한 RNN search 모델을 사용하여 시스템의 성능을 높였다. 인터넷 신문기사를 수집하여 구축한 한국어 문서요약 데이터 셋(train set 30291 문서, development set 3786 문서, test set 3705문서)으로 실험한 결과, input feeding과 copy mechanism을 포함한 모델이 형태소 기준으로 ROUGE-1 35.92, ROUGE-2 15.37, ROUGE-L 29.45로 가장 높은 성능을 보였다.