• 로봇학회논문지
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• 제5권4호
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• pp.294-301
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• 2010

In order to produce a convenient robot for the aged and the lower limb disabled, it is needed for the research detecting implicit walking intention and controlling robot by a user's intention. In this study, we developed sensor module system to control the walking- assist robot using FSR sensor and tilt sensor, and analyzed the signals being acquired from two sensors. The sensor module system consisted of the assist device control unit, communication unit by wire/wireless, information collection unit, information operation unit, and information processing PC which handles integrated processing of assist device control. The FSR sensors attached user's the palm and the soles of foot are sensing force/pressure signals from these areas and are used for detecting the walking intention and states. The tilt sensor acquires roll and pitch signal from area of vertebrae lumbales and reflects the pose of the upper limb. We could recognize the more detailed user's walking intention such as 'start walking', 'start of right or left foot forward', and 'stop walking' by the combination of FSR and tilt signals can recognize.

• 로봇학회논문지
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• 제9권3호
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• pp.154-159
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• 2014

The Global Positioning System (GPS) is widely used to aid the navigation of aerial vehicles. However, the GPS cannot be used indoors, so alternative navigation methods are needed to be developed for micro aerial vehicles (MAVs) flying in GPS-denied environments. In this paper, a real-time three-dimensional (3-D) indoor navigation system and closed-loop control of a quad-rotor aerial vehicle equipped with an inertial measurement unit (IMU) and a low-cost light detection and ranging (LIDAR) is presented. In order to estimate the pose of the vehicle equipped with the two-dimensional LIDAR, an octree-based grid map and Monte-Carlo Localization (MCL) are adopted. The navigation results using the MCL are then evaluated by making a comparison with a motion capture system. Finally, the results are used for closed-loop control in order to validate its positioning accuracy during procedures for stable hovering and waypoint-following.

• 한국멀티미디어학회논문지
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• 제16권12호
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• pp.1393-1402
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• 2013

Hand gesture is one of the most popular communication methods in everyday life. In human-computer interaction applications, hand gesture recognition provides a natural way of communication between humans and computers. There are mainly two methods of hand gesture recognition: glove-based method and vision-based method. In this paper, we propose a vision-based hand gesture recognition method using Kinect. By using the depth information is efficient and robust to achieve the hand detection process. The finger labeling makes the system achieve pose classification according to the finger name and the relationship between each fingers. It also make the classification more effective and accutate. Two kinds of gesture sets can be recognized by our system. According to the experiment, the average accuracy of American Sign Language(ASL) number gesture set is 94.33%, and that of general gestures set is 95.01%. Since our system runs in real-time and has a high recognition rate, we can embed it into various applications.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.514-517
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• 1996

In solving multi-level knapsack problems, conventional heuristic approaches often assume a short-sighted plan within a static decision enviornment to find a near optimal solution. These conventional approaches are inflexible, and lack the ability to adapt to different problem structures. This research approaches the problem from a totally different viewpoint, and a new method is designed and implemented. This method performs intelligent actions based on memories of historic data and learning. These actions are developed not only by observing the attributes of the optimal solution, the solution space, and its corresponding path to the optimal solution, but also by applying human intelligence, experience, and intuition with respect to the search strategies. The method intensifies, or diversifies the search process appropriately in time and space. In order to create a good neighborhood structure, this method uses two powerful choice rules that emphasize the impact of candidate variables on the current solution with respect to their profit contribution. A side effect of so-called "pseudo moves", similar to "aspirations", supports these choice rules during the evaluation process. For the purpose of visiting as many relevant points as possible, strategic oscillation between feasible and infeasible solutions around the boundary is applied for intensification. To avoid redundant moves, short-term (tabu-lists), intermediate-term (cycle detection), and long-term (recording frequency and significant solutions for diversification) memories are used. Test results show that among the 45 generated problems (these problems pose significant or insurmountable challenges to exact methods) the approach produces the optimal solutions in 39 cases.lutions in 39 cases.

• Molecular & Cellular Toxicology
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• 제2권4호
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• pp.244-250
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• 2006

The detection of many synthetic chemicals used in industry that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this respect, to regulate and to evaluate the chemical hazard will be important to environment and human health. The genotoxicity of 3 synthetic chemicals was evaluated in L5178Y $tk^{+/-}$ mouse lymphoma cells in vitro. 9H-carbazole (CAS No. 86-74-8) did not induce significant mutation frequencies both in the presence and absence of metabolic activation system. 1, 3-Dichloro-2-propanol (CAS No. 96-23-1) revealed a significant increase of mutation frequencies in the range of $625-373\;{\mu}g/mL$ in the absence of metabolic activation system and $157-79\;{\mu}g/mL$ in the presence of metabolic activation system. And also, fenpropathrin (CAS No. 64257-84-7) appeared the positive results only in the absence of metabolic activation system. Through the results of MLA tk assay with 3 synthetic chemicals in L5178Y cells in vitro, we may provide the important clues on the genotoxic potentials of these 3 chemicals.

• Molecular & Cellular Toxicology
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• 제2권2호
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• pp.89-96
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• 2006

The detection of many synthetic chemicals used in industry that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this respect, to regulate and to evaluate the chemical hazard will be important to environment and human health. The clastogenicity of 11 synthetic chemicals was evaluated in Chinese hamster lung fibroblast cells in vitro. 1-Chloro-3-bromopropane CAS No. 109-70-6) induced chromosomal aberrations with significance at the concentration of $185.0\;{\mu}g/mL\;and\;1,600\;{\mu}g/mL$ both in the presence and absence of metabolic activation system, respectively. Triphenyl phosphite (CAS No. 101-02-0), which is one of the most cytotoxic chemical among 11 chemicals tested revealed no clastogenicity in the range of $95.0-4.9\;{\mu}g/mL$ both in the presence and absence of metabolic activation system. From the results of chromosomal aberration assay with 11 synthetic chemicals in Chinese hamster lung cells in vitro, 1-chloro-3-bromopropane revealed a positive clastogenic result in this study.

• 한국정밀공학회지
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• 제32권6호
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• pp.537-542
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• 2015

The measurement of 3D shape is important in inspecting the quality of product. In this paper, we present a 3D shape measurement system of fastener using a camera and a slit laser. Calibration structure with slits is used in the extrinsic calibration of the camera and laser. The pose of the camera and laser is computed under the same world coordinate system in the calibration structure. Reflection of laser light on the metal surface causes many difficulties in the robust detection of them on image. We overcome this difficulty by using color and dynamic programming. Motor stage is used to rotate the fastener to recover the whole 3D shape of the surface of it.

• 한국콘텐츠학회논문지
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• 제10권5호
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• pp.20-28
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• 2010

본 논문에서는 증강현실 환경에서 등장하는 3차원 공간상의 객체를 카메라와 손을 사용하여 조작할 수 있는 인터페이스를 제안한다. 일반적으로 3차원 움직임을 검출하기 위해서 마커를 사용하지만, 이러한 경우에는 객체를 등록하기 위해서 마커가 영상 내에 있어야 하며 추가적인 장비를 사용함으로서 몰입감의 저하를 초래한다. 이것을 극복하기 위해서 본 연구에서는 손을 하나의 평면으로 변환하고 손 모양의 변화를 검출하여 마커를 대체하는 방법을 제안한다. 또한 조명으로 인한 손의 색상 변화에 따른 객체의 등록 위치 변화를 칼만 필터를 적용하여 추적하였다. 실험결과, 제안한 알고리즘은 손의 원활한 움직임에 의한 객체의 3차원 조작이 가능함을 보였다.

• 생명과학회지
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• 제10권4호
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• pp.368-373
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• 2000

Enteroviruses in the environment pose a public health risk because they can be transmitted via the fecal-oral route through contaminated water, and low numbers are able to initiate an infection in humans. Because the levels of viruses typically found in environmental water and drinking water are low, they must be concentrated from hundreds to thousands of liters of water. Therefore, the main goal of this study was the development of a rapid, simple and efficient procedure to concentrate, isolate and detect enteroviruses from environmental water samples. Viruses were first concentrated by adsorption to 1 MDS cartridge filter and then eluted with approximately 0.5 liter of 1.5% beef extract/0.05M glycin(pH 9.4). In this study, several procedures to concentrate and purify intact viruses from beef extract obtained from the adsorbent filters were tested. Among them, organic floccuration was the best reliable method for reconcentration. sample volume could be reduced to 200∼400 folds and the efficiency of virus recovery through the procedure was over 72%. Finally, the samples were filtered through a membrane disk filter and then analyzed by either the plaque assay or combined cell culture-polymerase chain reaction.

• 대한기관식도과학회지
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• 제17권1호
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• pp.14-18
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• 2011

The diagnosis and treatment of early gastrointestinal cancers is the gastroenterologists' mission because of national cancer screening program in South Korea. The detection of early cancers is emphasized, because these were previously treated with surgical treatment can be currently cured with endoscopic treatment. Gastroenterologists who achieved at least on some level can make an exact diagnosis regardless of what type of endoscopy, but generally, there are some required conditions for an optimal diagnosis. First, clinically important lesions have to be detected easily. Second, the border and morphology of lesions have to be characterized easily. Third, lesions have to be diagnosed exactly. Precancers and early cancers are often subtle and can pose a challenge to gastroenterologists to visualize using standard white light endoscopy. The use of dye solutions aids the diagnosis of early gastrointestinal cancers, however, it is a quite cumbersome to use dye solutions all the time and the solution often bothers the exact observation by pooling into the depression or ulceration of the lesion. To overcome this weakness, newer endoscopes are now developed so called "image enhanced endoscopy" using optical and/or electronic methods such as narrow band imaging (NBI), autofluorescence imaging (AFI), i-scan, flexible spectral imaging color enhancement (FICE) and confocal endomicroscopy (CLE).