• Journal of Korean Neurosurgical Society
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• v.56 no.3
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• pp.248-253
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• 2014

Objective : Cortical dysplasia (CD) is one of the common causes of epilepsy surgery. However, surgical outcome still remains poor, especially with frontal lobe epilepsy (FLE), despite the advancement of neuroimaging techniques and expansion of surgical indications. The aim of this study was to focus on surgical strategies in terms of extent of resection to improve surgical outcome in the cases of FLE with CD. Methods : A total of 11 patients of FLE were selected among 67 patients who were proven pathologically as CD, out of a total of 726 epilepsy surgery series since 1992. This study categorized surgical groups into three according to the extent of resection : 1) focal corticectomy, 2) regional corticectomy, and 3) partial functional lobectomy, based on the preoperative evaluation, in particular, ictal scalp EEG onset and/or intracranial recordings, and the lesions in high-resolution MRI. Surgical outcome was assessed following Engel's classification system. Results : Focal corticectomy was performed in 5 patients and regional corticectomy in another set of 5 patients. Only 1 patient underwent partial functional lobectomy. Types I and II CD were detected with the same frequency (45.45% each) and postoperative outcome was fully satisfactory (91%). Conclusion : The strategy of epilepsy surgery is to focus on the different characteristics of each individual, considering the extent of real resection, which is based on the focal ictal onset consistent with neuroimaging, especially in the practical point of view of neurosurgery.

• Applied Science and Convergence Technology
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• v.24 no.5
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• pp.125-131
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• 2015

We investigated the thermal characteristics of rotating anode X-ray tube to develop it for digital radiography by using computer simulation. The target which is the area of the anode struck by electrons is the most important component to get a long life of X-ray tube. So we analyze the thermal characteristics of the target and rotor assembly according to their emissivity by using ANSYS transient thermal simulation and then compare with the measured data of the target temperature operating in aging process of X-ray tube. Especially, keeping the lead coated layer as the role of metal lubricant on ball bearing enables to prevent the noise in rotating anode. The simulation result showed that its temperature was under the melting point of the lead in X-ray tube for digital radiography with 1.2 mm large focal spot 0.6 mm small focal spot and 150 kV tube voltage. We also investigated the relationship between the diameter of the anode shaft and the temperature of the anode and rotor assembly. It has been confirmed that the smaller anode shaft could be good for the rotor thermal characteristics.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.6
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• pp.886-898
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• 1995

One of the ways to measure the distance in the computer vision is to use the focus and defocus. There are two methods in this way. The first method is caculating the distance from the focused images in a point (MMDFP: the method measuring the distance to the focal plane). The second method is to measure the distance from the difference of the camera parameters, in other words, the apertures of the focal planes, of two images with having the different parameters (MMDCI: the method to measure the distance by comparing two images). The problem of the existing methods in MMDFP is to decide the thresholding vaue on detecting the most optimally focused object in the defocused image. In this case, it could be solved by comparing only the error energy in 3x3 window between two images. In MMDCI, the difficulty is the influence of the deflection effect. Therefor, to minimize its influence, we utilize two differently focused images instead of different aperture images in this paper. At the first, the amount of defocusing between two images is measured through the introduction of regularization and then the distance from the camera to the objects is caculated by the new equation measuring the distance. In the results of simulation, we see the fact to be able to measure the distance from two differently defocused images, and for our approach to be robuster than the method using the different aperture in the noisy image.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.3
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• pp.299-305
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• 2015

In this paper, we propose a simple and low-cost fabrication method of polymer microlens using solvent-vapor-assisted reflow (SVAR). Metal molds for replication of polymer were fabricated using micro milling and the cylindrical shape of polymer was imprinted using hot-embossing process. The cylindrical shape of polymer was changed to hemispherical lens shape by SVAR. The characteristics of fabricated microlens were evaluated according to the condition of SVAR such as temperature and time. The focal length of polymer microlens could be controlled more easily in low-temperature and long-time condition than in high-temperature and short-time condition. That is, the level of concentrated light to focal point could be improved through the control of temperature and time. Also, we confirmed that toluene was more appropriate solvent than acetone in fabrication of PMMA polymer microlens using SVAR.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.298-303
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• 1994

Microlens arrays are fabricated by melting "islands" of thick photoresist on a glass substrate. Microlenses with diameters $25\mu\textrm{m}$, $50\mu\textrm{m}$, $100\mu\textrm{m}$are made. Their surface profiles are obtained by a scanning electron microscope and a mechanical surface profilometer. The wavefront of the microlenses is measured by phase-shifting techniques using a Mach-Zehnder-like configuration. Thereby wavefront errors, focal lengths. point spread functions are obtained. The microlens with the diameter of $100\mu\textrm{m}$ has focal length of $164\mu\textrm{m}$ and spot diameter is less than $5\mu\textrm{m}$..

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.536-540
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• 2003

A new concept of adaptive focusing, using a Rotman lens, is presented in this paper. A Rotman lens is a microwave lens which is able to focus microwave power on its focal arc or generate multiple beams. By adding the array of phase shifters between a Rotman lens and antenna elements, the wavefront can be adaptively modulated to focus objects distributed in short range rather than far-field zone. From the optical point of view, the propagations of the lens have been simplified from the Fresnel diffraction integral to the Fourier transform. Using Fourier Transform, a beam propagation method has been developed to show improvement of the resolution by controlling wavefront of wave propagating from an aperture-type antenna array. The beam width(or spot size) and intensity have been calculated for a focused beam propagating from an array having $10{\lambda}$ of its size. For the beam with $20{\lambda},\;30{\lambda}$, and $50{\lambda}$ of geometrical focal length, the half-power beamwidth (spot size) is about $1.1{\lambda},\;1.3{\lambda}$, and $1.9{\lambda}$, respectively.

• Journal of Haehwa Medicine
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• v.16 no.2
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• pp.349-353
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• 2007

Hyperhidrosis is a condition characterized by excessive sweating. It can be generalized or focal. Generalized hyperhidrosis involves the entire body and is usually part of an underlying condition, most often an infectious, endocrine or neurologic disorder. Focal hyperhidrosis is idiopathic, occurring in otherwise healthy people. The condition carries a substantial psychological and social burden, since it interferes with daily activities. We treated two male patients who had hyperhidrosis on the head. In the point of Differentiation of Syndrom(辨證), these subjects were diagnosed as Bi-Wi-Gi-Her (Pi-Wei-Qi-Xu 脾胃氣虛) and was administered revised Bojungikgi-tang (reserved Buzhongyiqi-tang, 補中益氣湯加味方). All of two cases had anorexia, dyspepsia, fatigue. After treatment hyperhidosis and other symptoms improved.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.1
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• pp.112-123
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• 1997

This study investigated the effect of high-rise buildings on the preference for rural landscapes. The study site was a Seoul suburban, Yong-in, which showed typical scenes of rural development. Slides used in the study were taken in Young-in along the national road 45(north-south) and national road 42(east-west). Forty slides reflecting typical characters of Young-in were selected. Among them, ten slides which were selected through factor analysis based on “ruralits”score were used as original slides. They represent ten landscape types. The simulation of original slides was based on the following aspects: a observation distance. number of buildings and landscape types. The preferences for the landscapes were tested by 200 respondents on 40 slides: Distance(2) ${\times}$ Landscape type(10) = 20 slides, Number of buildings(2) ${\times}$ Landscape type(10) = 20 slides. The following results are found: 1) When high-rise buildings are introduced into rural scenes, there are some vulnerable landscape types: the landscape with high “rurality”, the landscape with background skyline and the focal landscape. 2) The observation distance affects landscape preference. The hypothesis that the nearer the distance the lower the preferences, is accepted. However, there are some exceptions in 3 landscape types. 3) The hypothesis that the more the number of buildings, the lower the preferences, is rejected. The result is quite unexpected one. When a single building is introduced in natural scene, it draws more attention as a focal point than a group of buildings, and subsequently the visual impact is stronger.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.9
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• pp.986-994
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• 2012

This paper is concerned with the application of the vision control algorithm with weighting matrix in robot point placement task. The proposed vision control algorithm involves four models, which are the robot kinematic model, vision system model, the parameter estimation scheme and robot joint angle estimation scheme. This proposed algorithm is to make the robot move actively, even if relative position between camera and robot, and camera's focal length are unknown. The parameter estimation scheme and joint angle estimation scheme in this proposed algorithm have form of nonlinear equation. In particular, the joint angle estimation model includes several restrictive conditions. For this study, the weighting matrix which gave various weighting near the target was applied to the parameter estimation scheme. Then, this study is to investigate how this change of the weighting matrix will affect the presented vision control algorithm. Finally, the effect of the weighting matrix of robot vision control algorithm is demonstrated experimentally by performing the robot point placement.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.3
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• pp.71-81
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• 2007

This study focused on the one and only temple of on the coastline of the West Sea, Kimje's Manghae Temple and Mt. Jinbong. The purpose of this study was to research the unique sense of place of the area by researching the location and view that clearly shapes the identity of the landscape. The following are the results. 1. The cultural landscape of Manghae Temple and the natural landscape of Mt. Jinbong have characteristics which take in the coastline and skyline, respectively. Specifically, from the existential vertical-horizontal images of "sky - land - Mt. Jinbong" and "moon - cloud - sea", an ascending reflection of the landscape surroundings can be found. 2. The "Sea - Manghae temple - Mt. Jinbong - sky" is the representation of the moderate 'inside-space' which belongs to the particular landscape area and which also shows the topophilia to Manghae Temple. Through this kind of interpretation, the sense of place of Manghae Temple and Mt. Jinbong reveals an intra-structure of an Imaging Landscape implying harmony and moderation, which is a unified organization of the surrounding phenomena(Temple and Mountain) and the essence (the doctrine of Buddhism) that matches Jin-muk's asceticism and lifestyle. 3. While the cultural landscape of Manghae Temple has a strong religious reference, the natural landscape Mt. Jinbong emphasizes the geography of the landscape. In other words, the motivating factor of Manghae Temple is a metaphorical sense of place such as through the "prospect of the sea" or "the Western Sea Paradise" and Mt. Jinbong, the landmark of the Kimje-Mankyung Plains and the focal point of the West Sea sunset, is highlighted as a simile for this sense of place. 4. Keeping this sense of place and territory respectively and showing the. bond with the sense of place which develops rhythmically and continuously, Manghae Temple and Mt. Jinbong are sublimated into a unified intra-structure, which reflects the Imaging landscape characteristics of "Mt. Jinbong, a focal point of the Mankyung Plains facing the West Sea" and "Manghae Temple, looking out to sea".