• 치과방사선
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• 제29권2호
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• pp.507-521
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• 1999

Osteopetrosis is an uncommon hereditary bone disorder whose prominent radiologic feature characterized by increased bone density. The authors reported a 7-year-old male patient who referred from local dental clinic for dental problems such as early exfoliation of deciduous teeth(#54,73,83) and delayed eruption of permanent teeth(#31.41.36.46). The patient appeared as a poorly developed. Dental X-ray films showed early exfoliation of deciduous teeth, delayed eruption of permanent teeth, and rampant caries. Lateral view of skull demonstrated increased opacity of calvarium, facial bones, and skull base. Generally the skeletal density is greatly increased throughout all bones. Facial CT showed poor development of paranasal sinuses and mastoid air cells. No hematopoietic and neurologic complications such as anemia, thrombocytopenia, blindness and deafness were found. Also mental retardation was not found. The final diagnosis of this case was a osteopetrosis tarda. Sometimes patient with osteopetrosis tarda may be developed dental problems prior to severe systemic symptoms. The dentist can be the first clinician to see the patient. It is very important for the dentist to have the knowledge of the osteopetrosis and to care the patient's dental problems to prevent complication such as osteomyelitis of jaws.

• 환경영향평가
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• 제4권2호
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• pp.71-91
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• 1995

In order to develop an appropriate set of criteria applicable for environmental impact assessment (EIA) of natural forest 8 items are proposed. The criteria are vegetation distribution area (DA), distribution pattern (DP), size (S), diameter of breast height of tree (DBH), humus (H), sustainment (ST), successional stage (SS) and impact of adjacent ecosystem (IAE), Each criterion has an interval which minimum 1 score to maximum 5 score Forest Evaluation Index (FEI) was obtained as the sum of 8 criteria value. Above 70% is considered to be absolutely conservative and from 50% to 70% range of total score is to be considered conservative. In the case of the Sancho˘ng Pumping-up Power Plant of Mt. Chiri, 8 criteria were applied base on actual vegetation map. Pinus densiflora community got 73%(29 scores) and Quercus variabilis - Q. serrata community got 60%(24 scores). This may be said that this local vegetation has high ecological potentiality. These criteria cannot always be absolutely evaluation tool. So it is expected to take the more time to be developed further, and holistically added by the other field such as fauna, geological feature etc.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1102-1105
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• 2004

In this paper, the problem of a viewer's head tracking in a desktop-based interactive stereoscopic display system is considered. A fast and low-cost approach to the problem is important for such a computing environment. The system under consideration utilizes a shuttle glass for stereoscopic display. The proposed method makes use of an image taken from a single low-cost video camera. By using a simple feature extraction algorithm, the obtained points corresponding to the image of the user-worn shuttle glass are used to estimate the glass center, its local 'yaw' angle, as measured with respect to the glass center, and its global 'yaw' angle as measured with respect to the camera location. With these estimations, the stereoscopic image synthetic program utilizes those values to interactively adjust the two-view stereoscopic image pair as displayed on a computer screen. The adjustment is carried out such that the so-obtained stereoscopic picture, when viewed from a current user position, provides a close-to-real perspective and depth perception. However, because the algorithm and device used are designed for fast computation, the estimation is typically not precise enough to provide a flicker-free interactive viewing. An error concealment method is thus proposed to alleviate the problem. This concealment method should be sufficient for applications that do not require a high degree of visual realism and interaction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권9호
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• pp.3762-3781
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• 2020

Infrared pedestrian target recognition is a vital problem of significant interest in computer vision. In this work, a novel infrared pedestrian target recognition method that uses heterogeneous features with multi-kernel transfer learning is proposed. Firstly, to exploit the characteristics of infrared pedestrian targets fully, a novel multi-scale monogenic filtering-based completed local binary pattern descriptor, referred to as MSMF-CLBP, is designed to extract the texture information, and then an improved histogram of oriented gradient-fisher vector descriptor, referred to as HOG-FV, is proposed to extract the shape information. Second, to enrich the semantic content of feature expression, these two heterogeneous features are integrated to get more complete representation for infrared pedestrian targets. Third, to overcome the defects, such as poor generalization, scarcity of tagged infrared samples, distributional and semantic deviations between the training and testing samples, of the state-of-the-art classifiers, an effective multi-kernel transfer learning classifier called MK-TrAdaBoost is designed. Experimental results show that the proposed method outperforms many state-of-the-art recognition approaches for infrared pedestrian targets.

• 한국ITS학회 논문지
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• 제9권2호
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• pp.104-109
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• 2010

본 논문에서는 차량의 무선단말을 이용하여 유선 네트워크와 연결된 정보통신 시스템 서비스를 이용하는 텔레메틱스 환경에서 제3자의 도청이나 공격을 막기 위한 사용자 인증기술을 제안한다. 제안된 사용자 인증방식에서는 차량안의 사용자의 음성신호로부터 생성된 음성 바이오 키를 이용하여 패킷 음성데이터를 암호화하여 정보통신 시스템에 전송하고, 정보통신 시스템 서버에서는 암호화된 패킷 음성데이터로부터 사용자의 음성특징을 복원하여 미리 등록된 사용자의 음성 바이오 키와 비교하여 실시간으로 사용자를 인증한다. 실험을 통해 다양한 공격으로부터 제안된 방식에 대한 안정성을 분석하였다.

• 대한치과의사협회지
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• 제56권10호
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• pp.548-554
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• 2018

Choristoma is a growth of normal tissue that occurs at an abnormal region. In the oral cavity, osseous choristoma that has a normal bone feature mainly has been appeared. It is mainly occurred on the tongue. So, It can be found in dental practice or in discomfort in the mouth. Osseous choristoma in the oral cavity is extremely rare. But It can be treated excisional biopsy under local anesthesia. The prognosis is very good. This case is a report of osseous choristoma on the dorsal surface of the tongue. A 17-year-old female patient presented with a foreign body sensation of the tongue. A diameter of the mass is 0.7cm, and there is no pain. Panoramic radiographs showed a radiopaque image in the form of a double image. An excisional biopsy was performed and diagnosed as an osseous choristoma. 12 months after the resection, there were no signs of recurrence. Intraoral osseous choristoma is very rare, but it is clinically very simple and can be found in dental radiographs. We present this case because of Dentists who examine the oral cavity of the patient can easily diagnose the lesion and treat it by simple resection.

• 대한기계학회논문집
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• 제19권6호
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• pp.1431-1438
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• 1995

In this paper, we present a multiple-view stereo matching method in case of moving in the direction of optical axis with stereo camera. Also we analyze the obtainable depth precision to show that multiple-view stereo increases the virtual baseline with single-view stereo. This method decides candidate points for correspondence in each image pair and then search for the correct combinations of correspondences among them using the geometrical consistency they must satisfy. Adantages of this method are capability in increasing the accuracy in matching by using the multiple stereo images and less computation due to local processing. This method computes 3-D depth by averaging the depth obtained in each multiple-view stereo. We show that the resulting depth has more precision than depth obtainable by each independent stereo when the position of image feature is uncertain due to image noise. This paper first defines a multipleview stereo agorithm in case of moving in the direction of optical axis with stereo camera and analyze the obtainable precision of computed depth. Then we represent the effect of removing the incorrect matching candidate and precision enhancement with experimental result.

• ETRI Journal
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• 제36권3호
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• pp.418-428
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• 2014

In social network services, such as Facebook, Google+, Twitter, and certain postings attract more people than others. In this paper, we propose a novel method for predicting the lifespan and retweet times of tweets, the latter being a proxy for measuring the popularity of a tweet. We extract information from retweet graphs, such as posting times; and social, local, and content features, so as to construct prediction knowledge bases. Tweets with a similar topic, retweet pattern, and properties are sequentially extracted from the knowledge base and then used to make a prediction. To evaluate the performance of our model, we collected tweets on Twitter from June 2012 to October 2012. We compared our model with conventional models according to the prediction goal. For the lifespan prediction of a tweet, our model can reduce the time tolerance of a tweet lifespan by about four hours, compared with conventional models. In terms of prediction of the retweet times, our model achieved a significantly outstanding precision of about 50%, which is much higher than two of the conventional models showing a precision of around 30% and 20%, respectively.

• 한국환경복원기술학회지
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• 제19권5호
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• pp.11-17
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• 2016

The purposes of this research are to estimate area of greenable roof and to monitor maintaining of green roofs using World-View 2 images. The contents of this research are development of World-View 2 application technologies for estimation of green roof area and development of monitoring and maintaining of green roofs using World-View 2 images. The available green roof areas in Gwangjin-gu Seoul, a case for this study, were estimated using digital maps and World-View 2 images. The available green roof area is approximately 12.17% ($2,153,700m^2$) of the total area, and the roof vegetation accounts for 0.46% ($80,660m^2$) of the total area. For verification of the extracted roof vegetation, Vworld 3D Desktop map service was applied. The study results may be used as a decision-making tool by the government and local governments in determining the feasibility of green roof projects. In addition, the project implementer may periodically monitor to see whether roof greening has maintained for efficient management of projects, and a vast amount of World-View 2 images may be regularly used before and after the projects to contribute to sharing of satellite images information.

• 비파괴검사학회지
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• 제31권3호
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• pp.260-270
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• 2011

The electromechanical impedance(E/M)-based method detects local structural damages based on variations of electrical impedance signatures which are obtained from piezoelectric sensors bonded to the structure and excited in high frequency band. In this method, temperature changes may result in significant impedance variations and lead to erroneous diagnostic results of the structure. To tackle this problem, a new technique providing a 2-dimensional damage feature related to the temperature information is proposed to distinguish the structural damage from the undesirable temperature variation. For experimental tests to validate the proposed method, damages are introduced by bolt loosening to a bolt-jointed steel beam, and impedance signals are measured under varying temperature conditions through a piezoelectric sensor attached on the beam. A freely suspended piezoelectric sensor is additionally utilized to obtain temperature information indirectly from resistance signatures. From a relationship between the damage index (from a constrained sensor) and the temperature (from a freely suspended sensor or a temperature sensor), damages can be detected more clearly under varying temperature compared to other conventional approaches.