• 한국기계가공학회지
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• 제10권5호
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• pp.85-90
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• 2011

In this paper a design procedure via computer-aided molding simulation is presented to optimize the air-trap locations in a speaker encloser of mobile phone. The molding flow simulation reveals that the race-tracking phenomenon is the dominant feature in the current mold design. In obtaining an optimal filling pattern, the local modifications of the wall thickness such as in a flow leader attachment are considered as the primary control factor, and both the gate position and the filling time become the secondary control factor. In the one-at-a-time approach, the last location to be filled in the mold cavity could be successfully moved to the extremities of the part, allowing a natural ventilation of entrapped air through the mold parting plane.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1053-1059
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• 2010

This paper treats the DIS (Digital Image Stabilization) problem subject to base motions such as translation, rotation and zoom. For the local motion estimation from a raw image, the Harris corner detection algorithm is exploited to extract feature points, and comparing those of consecutive images, the zoom ratio (scale factor) is computed. For the global motion estimation, an equivalent model is derived to account for a 3-dimensional composite motion from which the center point and Euler angle can be determined. Finally, the motion compensation follows. To show the effectiveness of the present DIS scheme, experimental results for synthetic images are illustrated.

• 전자공학회논문지B
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• 제32B권12호
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• pp.1591-1602
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• 1995

A hybrid approach which includes edge- and region-based methods is considered. The modified non-linear Laplacian(MNL) filter is used for feature extraction. The matching algorithm has three steps which are edge, signed region, and residual region matching. At first, the edge points are matched using the sign and direction of edges. Then, the disparity is propagated from edge to inside region. A variable window is used to consider the local method which give accurate matched points and area-based method which can obtain full-resolution disparity map. In addition, a new relaxation algorithm for considering matching possibility derived from normalized error and regional continuity constraint is proposed to reduce the mismatched points. By the result of simulation for various images, this algorithm is insensitive to noise and gives full- resolution disparity map.

• 대한두경부종양학회지
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• 제18권1호
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• pp.87-90
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• 2002

Malignant melanoma of the nasal cavity occurs rarely. Malignant melanoma, originated from the upper respiratory tract including nasal cavity, has clinical feature of local recurrence and easily metastasizes to regional or distant lymph nodes, lung, and liver. Malignant melanoma originated from nasal cavity frequently shows tumor cell invasion, ulceration, or infection. Owing to these characteristics, complete surgical excision of the malignant melanoma in nasal cavity is not easy. And also the prognosis of this tumor is not so good because of a high recurrence rate. Recently the authors have recently experienced a case of malignant melanoma originated from the inferior turbinate, which was treated with lateral rhinectomy, total maxillectomy. The defect developed after surgical extirpation was reconstructed with rotational forehead flap.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권1호
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• pp.74-81
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• 2004

We propose a novel scheme to transmit high center frequency RF signals using electroabsorption devices (EADs) as frequency converters at the transmitter and the receiver. In this approach frequency heterodyning is employed for obtaining high center frequency. With the EAD as a detector/mixer at the receiver we demonstrated a smaller conversion loss than that of the conventional modulator/mixer. With EAD as a modulator/mixer at the transmitter and with two heterodyned lasers to generate an optical local oscillator (LO), we demonstrated a large reduction (${\sim}23dB$) in conversion loss, and the transmission is not limited by the optical saturation of the EAD. This transmission scheme has optical single-side-band transmission feature which greatly relieves the fiber dispersion effect.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1391-1392
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• 2008

The modulation quality of the I/Q modulator in a wireless transmitter usually affects system performance and it mostly depends on both a nonlinearity and a distortion, from the third order intermodulation(IM3) signal and the imperfection features such as an input amplitude error and a local phase error, respectively. This paper focused on how much the Single Sideband Ratio(SSR), which indicates the signal distortion, changes according to the variation of the imperfection features. Since a desired signal, side band and IM3 signals at the I/Q modulator output are also represented with those power series coefficients and the imperfection features, the effects of the imperfection features on SSR can be clearly analyzed.

• 한국농촌건축학회논문집
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• 제9권3호
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• pp.1-10
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• 2007

This study aims to discuss the location characteristics and present distribution of facilities in the rural community. The purpose of this study is to suggest the basic data of the planning of facilities corresponding to the living sphere in community. The circumstances, location and distribution of the rural area facilities was analyzed through field investigation and interview. lt is necessary for ameliorating the income of inhabitants and the status of living environment to make a general local plan in developing rural area. That will be a solution to tackle the decreasement of population in the rural area. The survey's result is observed different by the feature of rural area, adjacence with near rural center, scale of rural center. So a standard of the various facility's arrangement plan must be established, and it must be enlarged in rural area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.183-187
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• 2002

This paper proposes a remote control system that combines computer network and an autonomous mobile robot. We control remotely an autonomous mobile robot with vision via the internet to guide it under unknown environments in the real time. The main feature of this system is that local operators need a World Wide Web browser and a computer connected to the internet communication network and so they can command the robot in a remote location through our Home Page. This system offers an image compression method using motion H.263 concept which reduces large time delay that occurs in network during image transmission.

• Journal of Chest Surgery
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• 제26권6호
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• pp.496-500
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• 1993

Takaysu`s arteritis is an arteritis of unknown etiology involving larger elastic arteries. The end stage pathologic feature is vascular obstructive change and the resulting clinical manifestations are local ischemic symptoms such as syncope, visual disturbance, claudication of extremities, hypertension, and angina. Recently we have experienced one case of Takayasu`s arteritis involving aortic arch, left common carotid artery and left subclavian artery. The patient was 27 year-old female and she was admitted because of headache and neck pain. Aortogram revealed fusiform dilatation of left common carotid artery with focal narrowing on it`s distal portion. The patient underwent surgical resection and replacement of Dacron tube graft between distal and proximal left common carotid artery. 3 months after operation, she was readmitted because of shoulder pain and headache. Aortogram revealed focal narrowing of proximal left common carotid artery and total obstruction of left subclavian artery which caused subclavian steel syndrome. Aorto-left common carotid and aorto-left subclavian bypass graft replacement were done.

• Journal of Chest Surgery
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• 제19권3호
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• pp.489-493
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• 1986

Takayasu`s arteritis is an arteritis of unknown etiology involving larger elastic arteries such as aorta and its branches, pulmonary arteries, and rarely coronary arteries. The late pathologic feature is vascular obstructive change and the resulting clinical manifestations are local ischemic symptoms such as syncope, visual disturbance, claudication of extremities, hypertension, and angina. the disease occurs predominantly in females, with the age of onset between 10 and 30 years. Recently we have experienced one case of Takayasu`s arteritis involving aortic arch and all its major branches. The patient was 36 year-old female and she was admitted because of headache, blurred vision, and easy fatigability and motor weakness of upper extremities. Aortogram revealed total obstruction of both carotid arteries at the site of its origin and partial irregular obstructive change in the innominate artery and both subclavian arteries. Bypass graft surgery using Gore-Tex grafts was performed with successful result.