• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.269-278
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• 1998

The Planning characteristics of the canals linking river basins and estuary reservoirs have been reviewed in relation to the trend widening the areas of water resources planning. It has been also tried to justify the characteristics of the link canals in the history of irrigation development. It was concluded that the link canals were resulted from the most recent technology as far as irrigation systems were concerned, why these were long- and large-scale multipurpose canals ； the hydraulic heads of the link canals could be controlled easily ； and which consisted of open channels, pipelines and control reservoirs. The types and general characteristics of the canals have been reviewed, and the fundamental concept and characteristics in the planning of the canals have been described.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1328-1332
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• 2010

The enlargement of existing tunnels is required to cope with problems related to traffic congestion. Sometimes, the tunnel traffic must be maintained through existing tunnels during their reconstruction due to non-availability of detours. And excavation by drill and blasting is desired for widening a hard rock tunnel. In this case, the road must be closed for some period for blasting through analyzing of traffic volume. In this paper, a case study on some traffic countermeasures for tunnel enlargement by blasting was performed. And the traffic flow characteristics of some tunnels in domestic main city were analyzed.

• Journal of Chest Surgery
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• v.27 no.11
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• pp.938-941
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• 1994

Neurogenic tumors of the mediastinum may have an intraspinal component connected by a narrowed segment of tumor in the intervertebral foramen, then have symptoms of back pain,lower extremity tingling sensation. CT scan or MRI demonstrated a Dumbbell-shaped mass density compressing spinal canal, enlargement of the foramen, erosion of bone, and intervertebral widening. We report the analysis of the 18 cases of neurogenic tumors on posterior mediastinum and Dumbbell type tumors are 3 cases among the 18 cases. The neurilemmomas were 12 cases[67%], the ganglioneuroma were 5 cases[28%], and neuroblastoma was one case[5%]. The successful removal was done in all cases, a standard thoracotomy and laminectomy was done in Dumbbell type tumors.There was no postoperative neurological complications.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.126-132
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• 2007

We propose a power factor correction scheme using a LC resonant circuit in commercial frequency without switching devices. In this method, It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The result are confirmed by the theoretical and experimental implementations

• International Journal of Highway Engineering
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• v.19 no.4
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• pp.53-59
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• 2017

PURPOSES : This study deals with traffic accidents involving trucks. The objective of this study is to develop a traffic accident model for trucks at roundabouts. METHODS : To achieve its objective, this study gives particular attention to develop appropriate models using Poisson and negative binomial regression models. Traffic accident data from 2007 to 2014 were collected from TAAS data set of road traffic authority. Thirteen explanatory variables such as geometry and traffic volume were used. RESULTS : The main results can be summarized as follows: (1) two statistically significant Poisson models (${\rho}^2=0.398$ and 0.435) were developed, and (2) the analysis revealed the common variables to be traffic volume, number of exit lanes, speed breakers, and truck apron width. CONCLUSIONS : Our modeling reveals that increasing the number of speed breakers and speed limit signs, and widening the truck apron width are important for reducing the number of truck accidents at roundabouts.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.942-944
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• 1992

The free electron laser (FEL) is driven by electron beams with energies ranging from hundreds of kilovolt to hundreds of megavolt. Therefore the efficiency of FEL strongly depends on the beam quality. In this paper we examined the relation between applied voltage and magnetic field at the magnetically insulated cylindrical cold cathode for the high quality electron beam by the numerical analysis. As a result, we knew that the beam widening strongly depended on applied magnetic field and voltage.

• Journal of Korean Society of Transportation
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• v.6 no.2
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• pp.49-56
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• 1988

Alternate use of lane at a signalized intersection is a quite different control of the operation of an intersection. This control introduces a new stop line and signal before the original stop line. All of the lanes between the two stop lines are used for left turn traffic or through traffic at a time. The purpose of the control is increasing the capacity of a n intersection without widening the approach width. this paper contains a study on the condition of a application, the proper distances between the two stop lines, the reasonable offsets(rear) to guarantee clearing the vehicles of previous phase, the comparison of approach capacity between the existing control and this control. The study results reveals that the offsets(rear) are rather stable showing the range(maximum value minus minimum value) of it's value does not exceed 3.6 seconds according to the field data. The approach capacity will be increased by 27%, 43%, 59%, 84% when the distances between the stop lines are 30.0m respectively. The control might have theoretical limitation to operate in practice. So an experimental application of the control at some suitable intersections prior to expanding it.

• Journal of Chest Surgery
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• v.15 no.1
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• pp.129-135
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• 1982

Congenital pericardial defect is a rare anomaly, which was first described by M. Columbus in 1559. Four hundred years later the first clinical diagnosis was reported by Ellis et al. The congenital pericardial defect Is usually asymptomatic and Is found Incidentally at thoracotomy and autopsy, but it appears that partial absence of pericardium Is not Innocuous because of sudden death due to herniation of a portion of heart. We experienced congenital left pericardial defect in 20 year old female who was diagnosed as left ventricular aneurysm before operation. This patient complained of dyspnea on exertion and anterior chest discomfortness. Physical examination revealed Grade II pansystolic murmur on the 3rd and 4th intercostal space left sternal border. There were specific abnormal findings on the chest plain film, EKG, ultrasonography, and left ventriculography. On 9th July 1981, an operation was performed and found the left partial pericardial defect through which a large portion of left ventricle was herniated Into left pleural space. The method of operation was removal of adhesion and widening of the pericardial defect to avoid Incarceration. After operation, we observed marked Improvement of symptoms and disappearance of cardiac murmur.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.1
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• pp.101-107
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• 2011

A UAV is defined as a powered, aerial vehicle that does not carry a human operator, and can fly autonomously or be piloted remotely. UAV operations have increased dramatically during the past several years in both the public and private sectors. The utilization of UAV and the activities of diverse widening, now the challenge was how to operate and integrate UAV safely in the NAS. The purpose of this study is to look around the trend for operability of Smart UAV in the NAS and to provide its implications and the future direction of integrated operating airspace focusing on U.S. where R&D and demand of UAV are the most in the world.

• Korean Institute of Interior Design Journal
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• v.14 no.5 s.52
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• pp.123-132
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• 2005

The 21th century is rapidly turning to the era of supernational competition aimed at global customers. Under these circumstances, applying the value innovation to space which will be in charge of value creation is recognized as being essential to life. This study aims to newly define the conception, the viewpoint, and types on applying the value innovation to space, which has not been established logically yet. The purpose of analyzing cases where the innovation was applied at home and abroad is to provide basic logic to establish these concepts in real space design. This study is prospected to be the core strategy of growth cause for maintaining our industrial development, so it is suggested that accepting, widening, and developing it may enable us to prepare for the continued innovation to space.