• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.77-77
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• 2012

As interest has increased in the interaction between low-temperature plasmas and materials, the role of modeling and simulation of processing in plasma has become important in understanding the effects of charged particles and radicals in plasma applications. Thus in this presentation, we present the theoretical and experimental studies of electron impact cross section for plasma processing gas, such as plasma etching and deposition processes. Also, here the work conducted at the Data Center for Plasma Properties (DCPP) over last 7 years on the systematic synthesis and assessment of fundamental knowledge on low-energy electron interactions with plasma processing gases is briefly summarized and discussed.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1507-1512
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• 2014

Recognition of Korean pre-service elementary school teachers concerning the factor for the environmental class was investigated and analyzed by the factorial analysis. Korean pre-service elementary school teachers are aware of the factor of 'participation in environment' as well as the factor of 'environmental knowledge' for the environmental class. Furthermore, they had a very positive attitude about the factor of 'participation in environment'.

• Journal of Korean Neurosurgical Society
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• v.57 no.6
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• pp.484-486
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• 2015

Unilateral pedicle stress fracture accompanying spondylolytic spondylolisthesis is rare even in the elderly. Most are associated with major trauma, previous spine surgery, or stress-related activity. Here, the authors describe an unique case of unilateral pedicle fracture associated with spondylolytic spondylolisthesis at the L5 level, which was successfully treated by posterior lumbar interbody fusion with screw fixation at the L5-S1 level. As far as the authors' knowledge, no such case has been previously reported in the literature. The pathophysiological mechanism of this uncommon entity is discussed and a review of relevant literature is included.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.4
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• pp.386-392
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• 1990

This paper discribes a sonar-based certainty grid, the probabilistic representation of the uncertain and incomplete sensor knowledge, for autonomous mobile robot navigation. We use sonar sensor range data to build a map of the robot's surroundings. This range data provides information about the location of the objects which may exist in front of the sensor. From this information, we can compute the probability of being occupied and that of being empty for each cell. In this paper, a new method using Bayesian formula is introduced, which enables us to overcome some difficulties of the Ad-Hoc formula that has been the only way of updating the grids. This new formula can be applied to other kinds of sensors as well as sonar sensor. The validity of this formula in the real world is verified through simulation and experiment. This paper also shows that a wide angle sensor such as sonar sensor can be used effectively to identify the empty area, and the simultaneous use of multiple sensors and fusion in a certainty grid can improve the quality of the map.

• Journal of Trauma and Injury
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• v.28 no.4
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• pp.280-283
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• 2015

The adolescent Tillaux fracture is an avulsion fracture of the anterolateral corner of the distal tibial epiphysis caused by external rotation of the foot. This type of fracture occurs during epiphyseal fusion in adolescence. A difficult to detect Tillaux fracture was discovered on a preoperative radiograph, such fractures have rarely been reported to accompany a predominantly adult-type ankle fracture. Especially, to the best of our knowledge, no case of a trimalleolar ankle fracture in an adolescent with a Tillaux fracture has been reported. Thus, we present a case of a trimalleolar ankle fracture in a 15-year-old adolescent with a Tillaux fracture who was successfully treated surgically.

• Journal of Power System Engineering
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• v.5 no.4
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• pp.11-17
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• 2001

Micronization of sensor is a trend of the silicon sensor development with regard to a piezoresistive silicon pressure sensor, the size of the pressure sensor diaphragm have become smaller year by year, and a microaccelerometer with a size less than $200{\sim}300{\mu}m$ has been realized, In this paper, we study some of the bonding processes of SCS(single crystal silicon) insulator wafer for the microaccelerometer. and their subsequent processes which might affect thermal loads. The finite element method(FEM) has been a standard numerical modeling technique extensively utilized in micro structural engineering discipline for design of SCS insulator wafers. Successful temperature distribution analysis and design of the SCS insulator wafers based on the tunneling current concept using microaccelerometer depend on the knowledge about normal mechanical properties of the SCS and $SiO_2$ layer and their control through manufacturing processes.

• Journal of Korean Neurosurgical Society
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• v.52 no.6
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• pp.564-566
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• 2012

Non-Hodgkin's lymphoma rarely originates from bone, and even more infrequently from a vertebral body. Lymphoblastic lymphoma is a rare type of non-Hodgkin's lymphoma, and results from an abnormality in adaptive immune cells. A 27-year-old man presented with a two-month history of night sweats, weight loss, and severe back pain. Radiological studies demonstrated an osteolytic lesion compressing the subarachnoid space at the T11 level. Posterolateral fusion with decompression was performed and a pathologic examination confirmed lymphoblastic lymphoma of the B-cell precursor type. To our knowledge, this is the first report of solitary lymphoblastic lymphoma from B-cell precursors in of the thoracic spine. Herein, we discuss the presenting symptoms and the management of this rare case of lymphoblastic lymphoma.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.331-333
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• 1994

A learning method for induction motor trajectory using neuro-fuzzy networks (NFN) based on fusion of fuzzy logic theory and neural networks is proposed. The premise and consequent parameters of the NFN affecting the controllers performances are modified during the learning stages by the proposed learning method to implement an optimal controller only with pre-determined target trajectory and the least amount of knowledge about an induction motor. The induction motor position control system is simulated to verify the effectiveness of the learned NF controller(NFC). The simulation results shows that the proposed learning method has good dynamic performance and small steady state error.

• Proceedings of the KWS Conference
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• 1996.10a
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• pp.19-34
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• 1996

A review was made of fatigue failures of nuclear power plant components in Japan, which were experienced in service and during periodical inspection. No case has been recently reported of a service fatigue failure of a reactor pressure vessel itself, excluding nozzle corner cracks, that occurred many years ago. But, service fatigue failures have been occasionally experienced in piping systems, pumps, and valves, on which fatigue design seems to have been inadequately applied. The causes of fatigue failures can be divided into two categories: mechanical-vibration-induced fatigue and thermal-fluctuation-induced fatigue. Vibration-induced fatigue failure occurs more frequently than is generally thought. The lesson gleaned from the present survey is a recognition that a service fatigue failure may occur due to any one or a combination of the following factors: (1) lack of communication between designers and fabrication engineers, (2) lack of knowledge about a possibility of fatigue failure and poor consideration about the effects of residual stresses, (3) lack of consideration on possible vibration in the design and fabrication stages, and (4) lack of fusion or poor penetration in a welded joint.

• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.2
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• pp.13-21
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• 1997

This paper describes the effectiveness of laser pulse shaping in eliminating weld defects such as porosity, cracks and undercuts in pulsed Nd:YAG Laser welding. A large porosity was formed in a keyhole mode of deep penetration weld metal of any stainless steel. Solidification cracks were present in Type 303 with about 0.3%s. The conditions for the formation of porosity were determined in further detail in Type 316. With the objectives of obtaining a fundamental knowledge of formation and prevention of weld defects, the fusion and solidification behavior of a molten puddle was observed during laser spot welding of Type 310S. through high speed video photographing technique. It was deduced that cellular dendrite tips grew rapidly from the bottom to the surface, and consequently residual liquid remained at the grain boundaries in wide regions and enhanced the solidification cracking susceptibility. Several laser pulse shapes were investigated and optimum pulse shapes were proposed for the reduction and prevention of porosity and solidification cracking.