• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• 제24권1호
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• pp.95-105
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• 1994

The aim of this study was to evaluate the clinical, radiographic and histopathologic features of 23 cases of solitary bone cyst by means of the analysis of radiographs and biopsy specimens in 23 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chunbuk National University. The obtained results were as follows; 1. The incidence of solitary bone cyst was almost equal in males(52.2%) and in females(47.8%) and the prevalent age of the solitary bone cyst were the second decade(47.8%) and the third decade (21.7%). 2. In the signs and symptoms of solitary bone cyst, pain or tenderness revealed in 17.4%, swelling revealed in 13.0%, pain and swelling revealed in 21.7%, paresthesia revealed in 4.4% and 43.5% were asymptom and the tooth vitality involved in the solitary bone cyst, 76.5% were positive and 23.5% were either positive or negative. 3. In the location of the solitary bone cyst, 47.8% present posterior region, 21.7% present anterior region, 21.6% present anterior and posterior region, 4.4% present condylar process area. 4. In the hyperostotic border of the solitary bone cyst, 47.8% were seen entirely, 21.8% were seen partialy, and 30.4% were not seen. 5. In the change of tooth, 59.1% were intact, 18.2% were loss of the alveolar lamina dura, 13.6% were root resorption 4.55% were tooth displacement, 4.55% were root resorption and tooth displacement. 6. In the change of cortical bone of the solitary bone cyst, 39.1% were intact and 60.9% were thinning and expansion of cortical bone. 7. In the histopathologic findings of 9 cases, 33.3% were thin connective tissue wall, 11.1% were thickened myxofibromatous wall, 55.6% were thickened myxofibromatous wall with dysplastic bone formation.

• Journal of Advanced Marine Engineering and Technology
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• 제33권2호
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• pp.330-335
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• 2009

A fiber-optic liquid level sensor based on bending cantilever beam has been proposed. A fiber Bragg grating(FBG) embedded in the cantilever beam is used to sensing elements. The basic concept is elongation and constriction of the FBG corresponding to the liquid level variation. The best FBG position on the cantilever for obtaining the high sensitivity was 4 cm from the fixing point. When the liquid level moves up and down vertically, the Bragg wavelength is linearly shifted. But, the wavelength sensitivity of the FBG installed on the upper side of cantilever was four times better than that of the FBG equipped in the lateral side due to the difference of unit strain applied to the FBG. Intensity demodulation using the low-cost edge filter is used to interrogate the Bragg wavelength through converting the wavelength signals into the optical intensity ones. Experiment results show that the electrical output is exponentially proportional to the liquid level. But, it should be overcome for applying to the ships.

• Journal of Advanced Marine Engineering and Technology
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• 제32권8호
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• pp.1257-1262
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• 2008

A long-distance remote sensing of temperature and current based on a fiber Bragg grating (FBG) is proposed and demonstrated. The thermal expanding effect of the epoxy and the Er-doped fiber ring laser (EFRL) are applied to the sensor system to enhance the temperature and current sensitivity. An EFRL with a 5 km-single-mode fiber and a FBG shows a high extinction ratio of more than 60 dB and a low power fluctuation of less than 1 dB. The metal wires are used to supply the current to the sensors. When the NOA65 puts on the FBG as a thermal expanding material, the temperature and current sensitivity of the lasing wavelength shift are about $30\;pm/^{\circ}C$ and 3pm/mA, respectively. The proposed sensing scheme is useful for measurement of current or temperature at a distant object of more than several km.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권3호
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• pp.210-217
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• 2011

Purpose: This study was to evaluate the synergistic effects of combined therapy of steroid and anti-neoplastic drug injection on hypertrophic scars in a rabbit model. Methods: Adult male white rabbits weighing about 2.5 kg were used. After full thickness wounding (about 6 mm) over the ventral surface of each ear sized was made, either saline (control group), triamcinolone, 5-fluoruracil, and mixture of triamcinolone and 5-fluoruracil were injected once 16 days after the wound was made. Rabbits were sacrificed 2, 4 and 8 weeks after injection, and tissue specimens were prepared for histologic and histomorphometric examinations. Results: With the combined injection of triamcinolone and 5-fluoruracil, collagen fiber thickness was arranged in a somewhat irregular manner 2 weeks after injection. After 4 weeks, blood vessels and inflammatory cells were decreased, and collagen fibers were arranged in an almost parallel manner. By 8 weeks, almost same amount of connective tissue compared with adjacent normal tissue was observed. Conclusion: These results indicated that combined injection of triamcinolone and 5-fluoruracil reduced the amount of hypertrophic scars by inhibition of fibroblasts and inflammatory cells. Therefore, combined injection of triamcinolone and 5-fluoruracil is a more potent and effective treatment of hypertrophic scars compared with the single injection of either triamcinolone or 5-fluorouracil.

• Journal of Advanced Marine Engineering and Technology
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• 제36권8호
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• pp.1111-1116
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• 2012

At present, indoor optical wireless communications using LED lightings has been widely studied. The combination of this technology to the low voltage powerline grid installed in each home makes an efficient method for fulfilling the premise of broadband access for home networking. In this paper, white LEDs were used for both illumination and remote-control, so that information can be broadcast within a room for control the optical wireless systems. We implemented a model car to evaluate the performance of optical wireless remote-control. The requirement for levels of illumination suitable for communication were investigated and applied to design the test-bed. In spite of limitation of line-of-sight communications, it will open up new applications to the optical wireless remote control system in an electromagnetic interference region.

• Journal of Advanced Marine Engineering and Technology
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• 제36권2호
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• pp.309-314
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• 2012

In this paper, we present surface-to-underwater visible light communication systems using white LEDs. Pulse position modulation (PPM)-based analogue data communications and on-off keying-based digital data communications systems are developed. Inexpensive and commercial power-LEDs and photo-diodes are used to construct two types of systems. We report the experimental results obtained from the prototype systems to show the possibility of an optical underwater visible light transceiver as a basis for short range underwater wireless network. Their performance deteriorates more than the atmosphere's one because of attenuation and scattering of the light in water, but these results are promising for the potential to create more robust network interface that improve medium performance such as a LED modulation and a photo-detector demodulation.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.506-511
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• 2011

In this paper, a rectenna for wireless power transmission at 900MHz is proposed. Rectenna is a device transforming RF power into DC power and it may consist of a antenna, rectifying and charging circuits. In this paper, we designed a slot antenna to receive 900MHz signal, a rectifying circuit of about 40% efficiency at 0dBm input, and a charging circuit to store a weak power signal and supply constant voltage to load. From the experiment using a RFID reader as a transmitter for 1W power, it was found that the proposed rectenna receiving about 0dBm power can supply 3.3V constant voltage to 50$k{\Omega}$ load during 280sec.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.500-505
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• 2011

In this paper, two types of micro-optic submersion detection systems are proposed and demonstrated. The structures are based on the transmission and reflection of incident light, respectively. Two collimators are separated by 10 mm and installed face to face in straight line. The incident light transmits from one side of collimator to the other through the air, but the optical loss is below 1 dB. On the other hand, when the sensors are submersed into water, most of optical power scattered into water. The systems monitor the dramatical power change to alarm the submersion. Reflection type of sensor system has a Bragg grating at the end of the sensor for back-reflection of sensing signal. This is for simple configuration of systems. The performance of two sensor systems are described in detail.

• Journal of Advanced Marine Engineering and Technology
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• 제35권1호
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• pp.102-107
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• 2011

LED-based lighting motivated by significant energy savings provides an opportunistic development of widespread free-space optical communications. Their transceivers have a variety of competitive advantages over RF including high bandwidth density, reliability, lower energy consumption, and long lifetime. But, it is difficult for existing buildings and structures such as ships and vehicles to install the communication cable to the ceiling. In this paper, controller area network (CAN)-based LED lighting communication systems were proposed. Results indicate the viability of developing inexpensive CAN interface modules and transceivers might be embedded in lighting products to support the indoor wireless networking.

• Proceedings of the KSME Conference
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.136-141
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• 2007

This paper introduces an artificial neuron which is a nano composite continuous sensor. The continuous nano sensor is fabricated as a thin and narrow polymer film sensor that is made of carbon nanotubes composites with a PMMA or a silicone matrix. The sensor can be embedded onto a structure like a neuron in a human body and it can detect deteriorations of the structure. The electrochemical impedance and dynamic strain response of the neuron change due to deterioration of the structure where the sensor is located. A network of the long nano sensor can form a structural neural system to provide large area coverage and an assurance of the operational health of a structure without the need for actuators and complex wave propagation analyses that are used with other methods. The artificial neuron is expected to effectively detect damage in large complex structures including composite helicopter blades and composite aircraft and vehicles.