• Journal of the Korea Society for Simulation
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• v.7 no.2
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• pp.63-78
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• 1998

The hierarchical cell structure consists of the macrocell and microcells to increase the system capacity and to achieve broad coverage. The hierarchical cell structure provides services for users in different mobility. In this paper, an analytical queueing model in mobile networks is proposed for the performance evaluation of the hierarchical cell structure. The model for networks with the multiple levels can simplify multi-dimensional ones into one-dimensional queueing model. The computational advantage will be growing as the layers are constructed in multiple levels. The computer simulation is provided for validating the proposed analytical model.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.466-470
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• 2011

This paper proposes the new method based on fuzzy logic which recognizes between normal and abnormal. The object image was the Thyroid Gland cell image that was diagnosed as normal and abnormal(two types of abnormal : follicular neoplastic cell, and papillary neoplastic cell), respectively. The nuclei were successfully diagnosed as normal and abnormal. The multiple feature parameters (pre-obtained 16 feature parameters of image data) were used to extract the features of each nucleus. As a consequence of using fuzzy logic algorithm, proposed in this paper, average recognition rate of 98.25% was obtained.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.8
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• pp.724-732
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• 2013

In this paper, we analyze a performance of multiuser massive multiple-input and multiple-output (MIMO) system. We derive the ergodic cell capacity based on a downlink frame structure and analyze the ergodic cell capacity with respect to the number of base station (BS) antennas and the number of users. This paper shows that the ergodic cell capacity is a concave function with respect to the number of BS antennas and the number of users, and also derives the optimal numbers of BS antennas and users for the maximum cell capacity. The simulation results verify the derived analyses and show that the derived numbers of BS antennas and users provide the maximum cell capacity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.635-656
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• 2019

In this paper, we investigate the degrees of freedom (DoF) of a multi-cell multi-user multiple-input multiple-output (MIMO) interference broadcast channel (IBC) with non-cooperation distributed base stations (BS), where each BS serves users of its corresponding cell. When all BSs simultaneously transmit their own signals over the same frequency band in the MIMO IBC, the edge users in each cell will suffer the inter-cell interference (ICI) and inter-user interference (IUI) signals. In order to eliminate the ICI and IUI signals, a distributed space time interference alignment (DSTIA) approach is proposed where each BS has only limited access to distributed moderately-delay channel state information at the transmitter (CSIT). It is shown that the DSTIA scheme can obtain the appreciate DoF gains. In addition, the DoF upper bound is asymptotically achievable as the number of antenna at each BS increases. It is shown that the DSTIA method can get DoF gains over other interference alignment schemes with delayed CSIT in literature. Moreover, the DSTIA method can attain higher DoFs than the IA schemes with global CSIT for certain antenna configurations.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.1
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• pp.7-12
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• 2014

Nevoid basal cell carcinoma syndrome (NBCCS) is inherited as an autosomal dominant trait with variable conditions, including multiple basal cell carcinoma, numerous keratocystic odontogenic tumors (KOTs) in the jaws, ectopic calcification of the falx cerebri, bifid ribs, macrocephaly, kyphoscoliosis, cleft palate, frontal and temporal bossing, mild ocular hypertelorism, mild mandibular prognathism, vertebral fusion, and so on. A 16-year-old boy visited the Dong-A University Medical Center, requiring diagnosis and treatment of multiple cystic lesions. He presented with many conditions related to NBCCS, including multiple KOTs, bifid rib, cleft lip, frontal bossing, mild ocular hypertelorism, and mild mandibular prognathism. No characteristic cutaneous manifestations (nevoid basal cell carcinoma) were observed in this patient. We report on a case of multiple KOTs associated with NBCCS with a review of the literature.

• The Journal of Korea Robotics Society
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• v.2 no.2
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• pp.137-142
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• 2007

In an information-oriented society, visually impaired persons also should obtain the information with relative ease. They tend to receive the information of letters by tactile sensation through braille display systems. Several types of braille display systems have been suggested so far, but none of them have been widely used yet. The braille display system should provide multiple lines of braille units to improve the level of understanding. In this paper, we propose a cell type braille unit with $3{\times}2$ dots, each of which consists of a piezoelectric linear motor. A braille cell is small and lightweight enough to be portable, and it can be easily assembled in multiple lines. The preliminary tests using the proposed braille display system show that it can provide the information that can be well perceived by visually impaired persons.

• Journal of the Optical Society of Korea
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• v.13 no.3
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• pp.335-340
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• 2009

Ultrashort pulse laser drilling of polycarbonate track-etched membrane (pTEM) material was used to fabricate a mouse embryo cell trapping device. Holes with a diameter of $2{\mu}m$ to $5{\mu}m$ were fabricated on a $10{\mu}m$ thick membrane using a femtosecond laser with a 150 fs pulse width and 775 nm wavelength and multiple-pulse irradiation. In cell trapping tests, the overall cell occupancy of the machined holes in the fabricated pTEM was found to be more than 80%. The results of a single pulse and multiple pulse irradiation were compared in terms of the surface quality. It was generally found that a single pulse with high energy was less desirable than irradiation with multiple pulses of lower energy.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.47-54
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• 2019

This study is concerned with the mechanism and structure of an optical microscope and an automatic multi-focus algorithm for automatically selecting sharp images from multiple foci of a cell. To obtain precise cell images quickly, a z-axis actuator with a resolution of $0.1{\mu}m$ was designed to control an optical microscope Moreover, a lighting control system was constructed to select the color and brightness of light that best suit the object being viewed. Cell images are captured by the instrument and the sharpness of each image is determined using Gaussian and Laplacian filters. Next, cubic spline interpolation and peak detection algorithms are applied to automatically find the most vivid points among multiple images of a single object. A cancer cell imaging experiment using propidium iodide staining confirmed that a sharp multipoint image can be obtained using this microscope. The proposed system is expected to save time and effort required to extract suitable cell images and increase the convenience of cell analysis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.2
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• pp.136-140
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• 2002

Basal cell nevus syndrome is inherited as an autosomal dominant trait with variable expressivity. This syndrome comprises a number of abnormalities such as multiple nevoid basal cell carcinomas of the skin, skeletal abnormalities as bifid rib and fusion of vertebrae, central nervous system abnormalities as mental retardation, eye abnormalities, and multiple odontogenic kerato cysts. In 1960, Gorlin and Goltz first described the features of this disease as constituting a true syndrome; since then, it has been realized that it is much more complex and encompassing than initially thought. This patient has many symtoms of basal cell nevus syndrome. - we has known multiple jaw cysts through panorama and facial computed tomography. He has hyperchromatism on basal cell through skin biopsy. In ophthalmologic consult, he has blindness on right. On his past medical history, amputation was done on his toes for polyductalism. - So we report with literature reviews

• Journal of Communications and Networks
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• v.17 no.3
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• pp.267-274
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• 2015

Due to the difficulty of coordination in the cellular uplink, it is a practical challenge how to achieve the optimal throughput scaling with distributed scheduling. In this paper, we propose a distributed and opportunistic user scheduling (DOUS) that achieves the optimal throughput scaling in a single-input multiple-output interfering multiple-access channel, i.e., a multi-cell uplink network, with M antennas at each base station (BS) and N users in a cell. In a distributed fashion, each BS adopts M random receive beamforming vectors and then selects M users such that both sufficiently large desired signal power and sufficiently small generating interference are guaranteed. As a main result, it is proved that full multiuser diversity gain can be achieved in each cell when a sufficiently large number of users exist. Numerical evaluation confirms that in a practical setting of the multi-cell network, the proposed DOUS outperforms the existing distributed user scheduling algorithms in terms of sum-rate.