• Journal of Korean Neurosurgical Society
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• 제54권4호
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• pp.344-346
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• 2013

A 55-year-old female patient presented with lower back pain and neurogenic intermittent claudication and underwent L3-L4 posterolateral fusion. To prepare the bone fusion bed, the transverse process of L3 and L4 was decorticated with a drill. On the 9th post-operative day, the patient complained of a sudden onset of severe abdominal pain and distension. Abdominal computed tomography revealed retroperitoneal hematoma in the right psoas muscle and iatrogenic right L3 transverse process fracture. Lumbar spinal angiography showed the delayed hematoma due to rupture of the 2nd lumbar artery pseudoaneurysm and coil embolization was done at the ruptured lumbar artery pseudoaneusyrm. Since then, the patient's postoperative progress proceeded normally with recovery of the hemodynamic parameters.

• 접착 및 계면
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• 제21권1호
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• pp.1-5
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• 2020

Heated tool joining is a popular method for joining parts made from plastics and composite materials. The method is commonly known as butt fusion in the plastic pipe industry and this paper provides a short introduction to the basics of producing a good butt fusion joint. The function of each of the essential parts of the butt fusion equipment is described followed by a presentation of the important parameters of the bonding process in reference to a well-established interfacial pressure versus time curve. The butt fusion procedure is then outlined with good practices that detail the preparation of equipment and pipes to be joined as well as the fusion joining process.

• 설비공학논문집
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• 제15권8호
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• pp.652-660
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• 2003

T-history method, measuring heat-of-fusion of phase change material (PCM) in sealed tubes, has the advantages of a simple experimental device and no requirements in sampling process. However, a degree of supercooling used in selecting the range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion in the original method, which has been improved in order to predict better results by us. In the present study, the modified method was applied to a variety of PCM such as paraffin and lauric acid having very small or no supercooling with a satisfactory precision. Also the selection of inflection point and temperature measurement position was fumed out not to affect the accuracy of heat-of-fusion significantly. As a result, the method can provide an appropriate means to assess a new developed PCM by cycle test even if a very accurate value cannot be obtained.

• 응용통계연구
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• 제17권3호
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• pp.605-617
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• 2004

데이터마이닝에서 가장 중요한 요소 중 하나는 마이닝에 사용될 데이터의 질이다. 질 높은 데이터를 바탕으로 마이닝이 수행될 때, 데이터마이닝의 잠재적 가치는 증대될 것이다. 본 논문에서는 지식발견 과정 중 데이터의 질을 향상시키기 위한 한 단계인 데이터 보강을 위해 데이터 통합 기법을 제안하고, 모의실험을 통해 제안된 알고리즘의 효율성을 비교하였다. 실험결과 제안된 알고리즘이 데이터 통합의 성능을 향상시킴을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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• pp.3092-3107
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• 2019

Visible-infrared image fusion is a process of synthesizing an infrared image and a visible image into a fused image. This process synthesizes the complementary advantages of both images. The infrared image is able to capture a target object in dark or foggy environments. However, the utility of the infrared image is hindered by the blurry appearance of objects. On the other hand, the visible image clearly shows an object under normal lighting conditions, but it is not ideal in dark or foggy environments. In this paper, we propose a multi-guided filter and a real-time image fusion method. The proposed multi-guided filter is a modification of the guided filter for multiple guidance images. Using this filter, we propose a real-time image fusion method. The speed of the proposed fusion method is much faster than that of conventional image fusion methods. In an experiment, we compare the proposed method and the conventional methods in terms of quantity, quality, fusing speed, and flickering artifacts. The proposed method synthesizes 57.93 frames per second for an image size of $320{\times}270$. Based on our experiments, we confirmed that the proposed method is able to perform real-time processing. In addition, the proposed method synthesizes flicker-free video.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3342-3351
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• 2023

High-density polyethylene (HDPE) pipelines in nuclear power plants (NPPs) have to meet high requirements for seismic performance. HDPE pipes have been proved to have good seismic performance, but joints are the weak links in the pipelines, and pipeline failures usually initiate from the defects inside the joints. Limited data are available on the seismic performance of butt-fusion joints of HDPE pipelines in NPPs, especially in terms of defects changes inside the joints after earthquakes. In this paper, full-scale shaking table tests were performed on a test section of suspended HDPE pipelines in an NPP, which included straight pipes, elbows, and 10 butt-fusion joints. During the tests, the seismic load-induced strain of the joints was analyzed by strain gauges, and it was much smaller than the internal pressure and self-weight-induced strain. Before and after the shaking table tests, phased array ultrasonic testing (PA-UT) was conducted to detect defects inside the joints. The locations, numbers, and dimensions of the defects were analyzed. It was found that defects were more likely to occur in elbows joints. No new defect was observed after the shaking table tests, and the defects showed no significant growth, indicating the satisfactory seismic performance of the butt-fusion joints.

• 한국분말재료학회지
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• 제27권1호
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• pp.44-51
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• 2020

Powder characteristics, such as density, size, shape, thermal properties, and surface area, are of significant importance in the powder bed fusion (PBF) process. The powder required is exclusive for an efficient PBF process. In this study, the particle size distribution suitable for the powder bed fusion process was derived by modeling the PBF product using simulation software (GeoDict). The modeling was carried out by layering sintered powder with a large particle size distribution, with 50 ㎛ being the largest particle size. The results of the simulation showed that the porosity decreased when the mean particle size of the powder was reduced or the standard deviation increased. The particle size distribution of prepared titanium powder by the atomization process was also studied. This study is expected to offer direction for studies related to powder production for additive manufacturing.

• Nuclear Engineering and Technology
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• 제40권6호
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• pp.439-450
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• 2008

The KSTAR device succeeded in first plasma generation on $13^{th}$ June of 2008 through comprehensive system test and commissioning. Among various kinds of the key factors that decisively affected the project, success in the construction and assembly of the major tokamak structure was most important one. Every engineering aspects of each structure were finally confirmed in the integrated commissioning period, and there were no severe troubles and failures prevented the KSTAR device from operating during the commissioning and the first plasma experiments. As a result, all of the experiences and technologies achieved through the KSTAR construction process are expected to be important fundamentals for future construction projects of superconducting fusion devices. This paper summarizes key engineering features of the major structures and of the machine assembly.

• 한국공작기계학회논문집
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• 제11권3호
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• pp.72-79
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• 2002

Though the laser cutting process is increasingly used in industry, a process automation and systematic database is still yet to be developed. In this study, as the fundamental step toward the construction of a reliable process expert system, a laser cutting quality monitoring/analysis system is developed based on simulations and experimental results. The relations between laser process parameters and laser cutting surface quality parameters such as kerf geometry, striation, surface roughness and dross formation are characterized and analyzed. A graphical user interface is used to visualize the results.

• Journal of the Korean Data and Information Science Society
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• 제18권4호
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• pp.927-935
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• 2007

Currently, Gyeongnam province is executing the social index survey every year to the provincials. But, this survey has the limit of the analysis as execution of the different survey per 3 year cycles. The solution of this problem is data fusion. Data fusion is the process of combining multiple data in order to provide information of tactical value to the user. But, data fusion doesn#t mean the ultimate result. Therefore, efficient analysis for the data fusion is also important. In this study, we present data fusion method of statistical survey data. Also, we suggest application methodology of association rule mining by clustering through data fusion of statistical survey data.