• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.5-9
• /
• 2004

In this paper, we studied the OCT(Optical Coherence Tomography) system which it has been extensively studied because of having some advantages such as high resolution cross-sectional images, low cost, and small size configuration. A basic principle of OCT system is Michelson interferometer. The characteristics of light source determine the resolution and the transmission depth. As a results, the light source have a commercial SLD with a central wavelength of 1,285 nm and FWHM(Full Width at Half Maximum) of 35.3 nm. The optical delay line part is necessary to equal of the optical path length with scattered light or reflected light from sample. In order to equal the optical path length, the stage which is attached to reference mirror is moved linearly by step motor And the interferometer is configured with the Michelson interferometer using single mod fiber, the scanner can be focused of the sample by using the reference arm. Also, the 2-dimensional cross-sectional images were measured with scanning the transverse direction of the sample by using step motor. After detecting the internal signal of lateral direction at a paint of sample, scanner is moved to obtain the cross-sectional image of 2-demensional by using step motor. Photodiode has been used which has high detection sensitivity, excellent noise characteristic, and dynamic range from 800 nm to 1,700 nm. It is detected mixed small signal between noise and interference signal with high frequency After filtering and amplifying this signal, only envelope curve of interference signal is detected. And then, cross-sectional image is shown through converting this signal into digitalized signal using A／D converter. The resolution of the OCT system is about 30$\mu\textrm{m}$ which corresponds to the theoretical resolution. Also, the cross-sectional image of ping-pong ball is measured. The OCT system is configured with Michelson interferometer which has a low contrast because of reducing the power of feedback interference light. Such a problem is overcomed by using the improved inteferometer. Also, in order to obtain the cross-sectional image within a short time, it is necessary to reduce the measurement time for improving the optical delay line.

• Journal of the Korea Computer Graphics Society
• /
• v.19 no.2
• /
• pp.1-8
• /
• 2013

Captured human motion data has been widely utilized for understanding the mechanism of human motion and synthesizing the animation of virtual characters. Searching for desired motions from given motion data is an important prerequisite of analyzing and editing those selected motions. This paper presents a new method of content-based motion retrieval without the need of additional metadata such as keywords. While existing search methods have focused on skeletal configurations of body pose or planar trajectories of locomotion, our method receives a three-dimensional trajectory as its input query and retrieves a set of motion intervals in which the trajectories of body parts such as hands, foods, and pelvis are similar to the input trajectory. In order to allow the user to intuitively sketch spatial trajectories, we used the Leap Motion controller that can precisely trace finger movements as the input device for our experiments. We have evaluated the effectiveness of our approach by conducting a user study in which the users search for dozens of pre-selected motions from baseketball motion data including a variety of moves such as dribbling and shooting.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.9
• /
• pp.139-147
• /
• 2022

The goal of this study is to develop a mobile application so that a person who is new to chemistry can easily acquire the knowledge necessary for chemical structure learning using image tracking technology. The point of this study is to provide a new chemical structure learning experience by recognizing a two-dimensional picture, augmenting the chemical structure into a three-dimensional object, showing it on the user's screen, and using a service that simultaneously provides related information in multiple fields. characteristic. Login API and real-time database technology were used for safe and real-time data management, and an application was developed using image tracking technology for image recognition and 3D object augmentation service. In the future, we plan to use the chemical structure data library to efficiently load and output data.

• The KIPS Transactions:PartD
• /
• v.17D no.2
• /
• pp.157-166
• /
• 2010

More recently, RFID (Radio Frequency Identification) systems have begun to find greater use in various industrial fields. The use of RFID system in these application domains has been promoted by efforts to develop the RFID tags which are low in cost, small in size, and high in performance. The RFID applications enable the real-time capture and update of RFID tag information, while simultaneously allowing business process change through real-time alerting and alarms. These be developed to monitor person or objects with RFID tags in a place and to provide visibility and traceability of the seamless flows of RFID tags. In this time, the RFID readers should be placed in diverse locations, the RFID flows between these readers can be tested based on various scenarios. However, due to the high cost of RFID readers, it may be difficult to prepare the similar environment equipped with RFID read/write devices. In this paper, we propose a simulator to allow RFID application testing without installing physical devices. It can model the RFID deployment environment, place various RFID readers and sensors on this model, and move the RFID tags through the business processes. This simulator can improve the software development productivity by accurately testing RFID middleware and applications. In addition, when data security cannot be ensured by any fault, it can decide where the problem is occurred between RFID hardware and middleware.

• The KIPS Transactions:PartA
• /
• v.11A no.7 s.91
• /
• pp.555-562
• /
• 2004

Both global volume reduction and local shape changes of hippocampus within the brain indicate their abnormal neurological states. Hippocampal shape analysis consists of two main steps. First, construct a hippocampal shape representation model ; second, compute a shape similarity from this representation. This paper proposes a novel method for the analysis of hippocampal shape using integrated Octree-based representation, containing meshes, voxels, and skeletons. First of all, we create multi-level meshes by applying the Marching Cube algorithm to the hippocampal region segmented from MR images. This model is converted to intermediate binary voxel representation. And we extract the 3D skeleton from these voxels using the slice-based skeletonization method. Then, in order to acquire multiresolutional shape representation, we store hierarchically the meshes, voxels, skeletons comprised in nodes of the Octree, and we extract the sample meshes using the ray-tracing based mesh sampling technique. Finally, as a similarity measure between the shapes, we compute $L_2$ Norm and Hausdorff distance for each sam-pled mesh pair by shooting the rays fired from the extracted skeleton. As we use a mouse picking interface for analyzing a local shape inter-actively, we provide an interaction and multiresolution based analysis for the local shape changes. In this paper, our experiment shows that our approach is robust to the rotation and the scale, especially effective to discriminate the changes between local shapes of hippocampus and more-over to increase the speed of analysis without degrading accuracy by using a hierarchical level-of-detail approach.

• Cartoon and Animation Studies
• /
• s.36
• /
• pp.147-165
• /
• 2014

Around the turn of 21st century, there has been a major technological shift in the animation industry. With development of reality-based computer graphics, major American animation studios replaced hand-drawn method with the new 3D computer graphics. Traditional animation was known for its simplified shapes such as circles and triangle that makes characters' movements distinctive from non-animated feature films. Computer-generated animation has largely replaced it, but is under continuous criticism that automated movements and reality-like graphics devaluate the aesthetics of animation. Although hand-drawn animation is still produced, 3D computer graphics have taken commercial lead and there has been many changes to acting of animated characters, which calls for detailed investigation. Firstly, the changes in acting of 3D characters can be traced from looking at human-like rigging method that mimics humanistic moving mechanism. Also, if hair and clothing was part of hand-drawn characters' acting, it has now been hidden inside mathematical simulation of 3D graphics, leaving only the body to be used in acting. Secondly, looking at "Stretch and Squash" method, which represents the distinctive movements of animation, through the lens of media, a paradox arises. Hand-drawn animation are produced frame-by-frame, and a subtle change would make animated frames shiver. This slight shivering acts as an aesthetic distinction of animated feature films, but can also require exaggerated movements to hide the shivering. On the contrary, acting of 3D animation make use of calculated movements that may seem exaggerated compared to human acting, but seem much more moderate and static compared to hand-drawn acting. Moreover, 3D computer graphics add the third dimension that allows more intuitive movements - maybe animators no longer need fine drawing skills; what they now need is directing skills to animate characters in 3D space intuitively. On the assumption that technological advancement and change of artistic expressionism are inseparable, this paper compares acting of 3D animation studio Pixar and classical drawing studio Disney to investigate character acting style and movements.

• Journal of Broadcast Engineering
• /
• v.11 no.1 s.30
• /
• pp.3-14
• /
• 2006

Music summarization means a technique which automatically generates the most importantand representative a part or parts ill music content. The techniques of music summarization have been studied with two categories according to summary characteristics. The first one is that the repeated part is provided as music summary and the second provides the combined segments which consist of segments with different characteristics as music summary in music content In this paper, we propose and evaluate two kinds of music summarization techniques. The algorithm using multi-level vector quantization which provides a repeated part as music summary gives fixed-length music summary is evaluated by overlapping ration between hand-made repeated parts and automatically generated summary. As results, the overlapping ratios of conventional methods are 42.2% and 47.4%, but that of proposed method with fixed-length summary is 67.1%. Optimal length music summary is evaluated by the portion of overlapping between summary and repeated part which is different length according to music content and the result shows that automatically-generated summary expresses more effective part than fixed-length summary with optimal length. The cluster-based algorithm using 2-D similarity matrix and k-means algorithm provides the combined segments as music summary. In order to evaluate this algorithm, we use MOS test consisting of two questions(How many similar segments are in summarized music? How many segments are included in same structure?) and the results show good performance.

• The Korean Journal of Nuclear Medicine
• /
• v.28 no.1
• /
• pp.133-140
• /
• 1994

Recently, there are many considerations and studies on biological effects of radiations in radiation workers, as well as in accidentally or therapeutically irradiated persons. The most practical and reliable method of dosimetry for radiation accidents is the scoring of gross chromosomal aberrations in human lymphocytes (Ydr) as a biological dosimetry. By the way, although usual doses of $^{131}I$ administered therapeutically for thyroid cancer are ranging from 100 mCi to 200 mCi, there are differences of absorbed doses and Ydr, ranging from 0.004 to 0.04, on equally administered $^{131}I$ due to variations in metabolic characteristics, stage of tumors and physical status of subjects. In this study, We exert to obtain the dose-response relationships of $^{131}I$, as a good guide to evaluating acute effects of accidental irradiations and radiation induced leukemia or solid tumor, by in vitro induction of chromosomal aberrations. we studied the relationship between radiation dose (D) and the frequency of chromosomal aberrations (Ydr) obserbed in peripheral lymphocytes that were irradiated in vitro with $^{131}I$ at doses ranging from 0.05 to 6.00 Gy. By scoring cells with unstable chromosomal aberrations (dicentric chromosomes and ring chromosomes) we obtained this linear-quadratic dose response equation Ydr=0.064351 $D^2$-0.13143 D+0.045684 This dose-response relationship may be useful for evaluating acute and chronic $^{131}I$ induced biological effects.

• Journal of Chest Surgery
• /
• v.32 no.5
• /
• pp.422-427
• /
• 1999

Background: Tachycardia induced heart failure model would be the model of choice for the dilated cardiomyopathy. This more closely resembles the clinical syndrome and does not require major surgical trauma, myocardial ischemia and pharmacological or toxic depression of cardiac function. When heart failure is progressive, application of new surgical procedures to the faling heart is highly risky. It has been shown that recovery trajectory from heart failure is a new method in decreasing animal mortality. The purpose is to establish the control datas for recovery trajectory in the canine heart failure model. Material and Method: 21 mongrel dogs were studied at 4 stages(baseline, at the heart failure, 4 and 8 weeks after recovery). Heart failure was induced during 4 weeks of continuous rapid pacing using a pacemaker. Eight weeks of trajectory of recovery period was allowed. Indices of left ventricular function and dimension were measured every 2 weeks and the hemodynamics were measured by use of Swan-Ganz catheterization and thermodilution method every 4 weeks. Values were expressed as mean${\pm}$standard deviation. Result: 4(20%) dogs died due to heart failure. Left ventricular end-diastolic volume at the 4 stages were 40.8${\pm}$7.4, 82.1${\pm}$21.1, 59.9${\pm}$7.7 and 46.5${\pm}$6.5ml. Left ventricular end-systolic volume showed the same trend. Ejection fractions were 50.6${\pm}$4.1, 17.5${\pm}$5.8, 36.3${\pm}$7.3, and 41.5${\pm}$2.4%. Blood pressure and heart rate showed no significant changes. Pressures of central vein, right ventricle, pulmonary artery, and pulmonary capillary wedge showed significant increase during the heart failure period, normalizing at the end of recovery period. Stroke volumes were 21.5${\pm}$8.2, 12.3${\pm}$3.5, 17.9${\pm}$4.6, and 15.5${\pm}$3.4ml. Blood norepinephrine level was 133.3${\pm}$60.0pg/dL at the baseline and 479.4${\pm}$327.3pg/dL at the heart failure stage(p=0.008). Conclusion: Development of tachycardia induced heart failure model is of high priority due to ready availability and reasonable amenability to measurements. Recovery trajectory after cessation of tachycardia showed reduction of cardiac dilatation and heart function. Application of new surgical procedures during the recovery period could decrease animal mortality.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.5
• /
• pp.667-674
• /
• 2023

In the event of a disaster occurring within a building, the prompt and efficient evacuation and rescue of occupants within the building becomes the foremost priority to minimize casualties. For the purpose of such rescue operations, it is essential to ascertain the distribution of individuals within the building. Nevertheless, there is a primary dependence on accounts provided by pertinent individuals like building proprietors or security staff, alongside fundamental data encompassing floor dimensions and maximum capacity. Consequently, accurate determination of the number of occupants within the building holds paramount significance in reducing uncertainties at the site and facilitating effective rescue activities during the golden hour. This research introduces a methodology employing computer vision algorithms to count the number of occupants within distinct building locations based on images captured by installed multiple CCTV cameras. The counting methodology consists of three stages: (1) establishing virtual Lines of Interest (LOI) for each camera to construct a multi-camera network environment, (2) detecting and tracking people within the monitoring area using deep learning, and (3) aggregating counts across the multi-camera network. The proposed methodology was validated through experiments conducted in a five-story building with the average accurary of 89.9% and the average MAE of 0.178 and RMSE of 0.339, and the advantages of using multiple cameras for occupant counting were explained. This paper showed the potential of the proposed methodology for more effective and timely disaster management through common surveillance systems by providing prompt occupancy information.