• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.274.1-274.1
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• 2013

We report the circumferential alignment of human aortic smooth muscle cells (HASMCs) in an orthogonally micropatterned circular microfluidic channel to form an in vivo-like smooth muscle cell layer. To realize a biomimetic smooth muscle cell layer which is aligned perpendicular to the axis of blood vessel, we first fabricated a half-circular polydimethylsiloxane (PDMS) microchannel by soft lithography using a convex PDMS mold. The orthogonally micro wrinkle patterns were generated inside the half-circular microchannel by stretching-releasing operation under UV irradiation. Upon UV treatment with uniaxial 40 % stretch of a PDMS substrate and releasing process, the microwrinkle patterns perpendicular to the axial direction of the circular microchannel were generated, which could guide the circumferential alignment of HASMCs successfully during cultivation. The analysis of orientation angle, shape index, and contractile protein marker expression indicates that the cultured HASMCs revealed the in vivo-like cell phenotype. Finally, we produced circular microchannels by bonding two half-circular microchannels, and cultured the HASMCs circumferentially with high alignment and viability for 5 days. These results are the first demonstration for constructing an in vivo-like 3D smooth muscle cell layer in the circular microfluidic channel which can provide novel bioassay platforms for in-depth study of HASMC biology and vascular function.

• 한국엔터테인먼트산업학회논문지
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• 제5권2호
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• pp.87-95
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• 2011

최근 다양한 인터랙티브 인터페이스 개발로 인해 체감형 게임 환경에 관심이 모아지고 있다. 따라서 본 논문에서는 증강현실 기술의 하나인 마커인식 인터페이스와 멀티 터치 인터랙션 인터페이스를 이용한 멀티 카드 터치 기반의 인터랙티브 아케이드 시스템을 제안한다. 이를 위해 DI 기반의 인식 알고리즘을 적용하여 카드의 위치, 방향 정보를 인식한다. 또한 사용자의 손 제스처 정보를 트래킹하여 다양한 인터랙션 메타포를 제공한다. 본 시스템은 사용자에게 좀 더 높은 몰입감을 제공하며 새로운 경험을 제공한다. 따라서 제안하는 시스템은 체감형 아케이드 게임기기에 활용될 것이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권6호
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• pp.2289-2301
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• 2015

Mobile devices are becoming powerful enough to realize augmented reality (AR) application. This paper introduces two AR methods to estimate an environmental illumination distribution of a scene. In the first method, we extract the lighting direction and intensity from input images captured with a front-side camera of a mobile device, using its orientation sensor. The second method extracts shadow regions cast by three dimensional (3D) AR marker of known shape and size. Because previous methods examine per pixel shadow intensity, their performances are much affected by the number of sampling points, positions, and threshold values. By using a simple binary operation between the previously clustered shadow regions and the threshold real shadow regions, we can compute efficiently their relative area proportions according to threshold values. This area-based method can overcome point sampling problem and threshold value selection. Experiment results demonstrate that the proposed methods generate natural image with multiple smooth shadows in real-time.

• 농업과학연구
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• 제41권2호
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• pp.101-106
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• 2014

This study was conducted to identify lily species native to Korea from formosan lily (Lilium formosanum) belonging to Longiflorum section. Due to flowering time, flower color and orientation, long shelf life and resistant to diseases, the native lily species can be valuable genetic resources for interspecific hybrids. One of the chloroplast genes, matK, was used to clone and sequence to explore any base changes. The matK was successfully amplified into 1,539 bp (94% of the gene) and phylogenetic tree demonstrated 6 clades for those 11 lily species used in this study. There were one or two base substitutions among 10 lilies native to Korea, while formosan lily native to Taiwan exhibited 6 base substitutions in matK gene, rendering it genetically distant. A restriction enzyme NruI recognized one of the six base changes, and digested the matK gene of 10 native lily species only, but not in formosan lily. The confirmed cleavage characteristic of the target region in matK gene was designed into a CAPS (cleaved amplified polymorphic sequences) marker which will be available to estimate compatibility of interspecific hybridization and to trace the pedigree when those native lilies are crossed with the formosan lily.

• 한국산업융합학회 논문집
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• 제23권2_2호
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• pp.255-261
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• 2020

We consider the problem of autonomously flying a quadcopter in indoor environments. Navigation in indoor settings poses two major issues. First, real time recognition of the marker captured by the camera. Second, The combination of the distributed images is used to determine the position and orientation of the quadcopter in an indoor environment. We autonomously fly a miniature RC quadcopter in small known environments using an on-board camera as the only sensor. We use an algorithm that combines data-driven image classification with image-combine techniques on the images captured by the camera to achieve real 3D localization and navigation.

• 한국항행학회논문지
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• 제28권3호
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• pp.375-378
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• 2024

The instrument landing system (ILS) is an international standard established by the International civil aviation organization (ICAO) as one of the landing support facilities for aircraft. This system consists of a localizer (LOC) that provides orientation information about the runway to indicate the approach direction, a glide path (GP) that indicates the appropriate approach glide slope, and three of marker beacons (MB) that indicates the distance to the runway landing edge. In this study, we predicted the received signal strength by altitude and distance for LOC signals transmitted from the ground and analyzed the difference with the signal strength measured in the actual environment. Our objective is to develop signal strength prediction technology and apply it to the real environment.

• 로봇학회논문지
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• 제12권4호
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• pp.411-418
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• 2017

During the intramedullary nailing procedure, surgeons feel difficulty in manipulation of the X-ray device to align it to axes of nailing holes and suffer from the large radiation exposure from the X-ray device. These problems are caused by the fact the surgeon cannot see the hole's location directly and should use the X-ray device to find the hole's location and direction. In this paper, we proposed the robotic guidance of the distal screwing using an optical tracking system. To track the location of the hole for the distal screwing, the reference marker is attached to the proximal end of an intramedullary nail. To guide the drill's direction robustly, the 6-degree-of-freedom robotic arm is used. The robotic arm is controlled so as to align the drill guiding tool attached the robotic arm with the obtained the hole's location. For the safety, the robot's linear and angular velocities are restricted to the predefined values. The experimental results using the artificial bones showed that the position error and the orientation error were 0.91 mm and $1.64^{\circ}$, respectively. The proposed method is simple and easy to implement, thus it is expected to be adopted easily while reducing the radiation exposure significantly.

• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.579-584
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• 2016

When surgical instruments are tracked in an image-guided surgical navigation system, a stereo vision system with high accuracy is generally used, which is called optical tracker. However, this optical tracker has the disadvantage that a line-of-sight between the tracker and surgical instrument must be maintained. Therefore, to complement the disadvantage of optical tracking systems, an internal vision sensor is attached to a surgical instrument in this paper. Monitoring the target marker pattern attached on patient with this vision sensor, this surgical instrument is possible to be tracked even when the line-of-sight of the optical tracker is occluded. To verify the system's effectiveness, a series of basic experiments is carried out. Lastly, an integration experiment is conducted. The experimental results show that rotational error is bounded to max $1.32^{\circ}$ and mean $0.35^{\circ}$, and translation error is in max 1.72mm and mean 0.58mm. Finally, it is confirmed that the proposed tool tracking method using an internal vision sensor is useful and effective to overcome the occlusion problem of the optical tracker.

• 제어로봇시스템학회논문지
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• 제20권10호
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• pp.1044-1050
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• 2014

Robots used for pipe inspection have been studied for a long time and many mobile mechanisms have been proposed to achieve inspection tasks within pipelines. Localization is an important factor for an inpipe robot to perform successful autonomous operation. However, sensors such as GPS and beacons cannot be used because of the unique characteristics of inpipe conditions. In this paper, an inpipe localization algorithm based on elbow detection is presented. By processing the projected marker images of laser pointers and the attitude and heading data from an IMU, the odometer module of the robot determines whether the robot is within a straight pipe or an elbow and minimizes the integration error in the orientation. In addition, an off-line positioning algorithm has been performed with forward and backward estimation and Procrustes analysis. The experimental environment has consisted of several straight pipes and elbows, and a map of the pipeline has been constructed as the result.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.47-47
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• 2005

There are many different surface technologies currently applied for preparation of protein chips. However, it requires innovative surface chemistry for capture proteins to be immobilized on chip surface keeping their conformation and activity intact and their orientation right, while they bind tightly and densely in a given array spot. Proteogen has developed 'ProteoChip BP' coated with novel proprietary linker molecules $(ProLinker^{TM})$ for efficient and robust immobilizations of capture proteins by improving surface properties of molecular captures. It was demonstrated that $ProLinker^{TM}$ gave the best surface performance in preparation of protein microarray chip base plates among others currently available on the market. In particular, the $ProLinker^{TM}-based$ surface chemistry has demonstrated to provide excellent performance in preparation of 'Antibody Chip' for analysis of biomarkers as well as proteome expression profiles. The linker molecule has also shown to be well applicable for development of biosensors and micro-beads as well as protein microarray and nano-array. ProteoChip BP can be used either for preparation of high-density array by using a microarrayer or for preparation of 'Well-on-a-Chip' with low density array, which is better applicable for quantitative analysis of biomarkers or protein-protein interactions. The biomarker assay can be performed either by direct or sandwich methods of fluorescence immunoassay. Application of ProteoChip BP has been well demonstrated by the extensive studies of 1) tumor-marker assays, 2) new drug screening by using 'Integrin Chip' and 3) protein expression profile analysis. Some of experimental results will be presented.