• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.11
• /
• pp.105-114
• /
• 2015

This paper proposes methods to remove background area and segment region of interest (ROI) in chest X-ray images. Conventional algorithms to improve detail or contrast of images normally utilize brightness and frequency information. If we apply such algorithms to the entire images, we cannot obtain reliable visual quality due to unnecessary information such as background area. So, we propose two effective algorithms to remove background and segment ROI from the input X-ray images. First, the background removal algorithm analyzes the histogram distribution of the input X-ray image. Next, the initial background is estimated by a proper thresholding on histogram domain, and it is removed. Finally, the body contour or background area is refined by using a popular guided filter. On the other hand, the ROI, i.e., lung segmentation algorithm first determines an initial bounding box using the lung's inherent location information. Next, the main intensity value of the lung is computed by vertical cumulative sum within the initial bounding box. Then, probable outliers are removed by using a specific labeling and the pre-determined background information. Finally, a bounding box including lung is obtained. Simulation results show that the proposed background removal and ROI segmentation algorithms outperform the previous works.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.48 no.10
• /
• pp.1303-1310
• /
• 1999

In this paper, the Timed Petri-Nets(TPN) modeling of Modular Cell Manufacturing Systems(MCMS) was investigated to overcome the limit of batch mode operation, which has been one of the most popular manufacturing types to produce an extensive industrial output and to be able to adopt to suitable and quickly changing manufacturing environments. A model of the MCMS was developed in reference to the actual TFT-LCD manufacturing system. TFT-LCD manufacturing system is not mass-productive in batch mode, but it operates in the form of MCMS which consists of a sequence of several cells with four processes of operation, including those of color filter(C/F), TFT, cell, and module. The cell process is further regrouped in those of Front-End and Back-End. For the Back-End cell process, it is reconstructed into a virtual model, consisting of three cells. The TPN modeling encompasses those properties, such as states and operations of machines, the number of buffers, and the processing time. The performance of the modeling was further examined in terms of scheduling system. The productivity in each cells was examined with respect to the change of failure rate of the cell machines and Automatic Guided Vehicles(AGV) using simulation by TPN.

• Journal of Positioning, Navigation, and Timing
• /
• v.4 no.1
• /
• pp.9-16
• /
• 2015

The applications of Global Navigation Satellite System (GNSS) receivers are becoming wider in various commercial and military systems including even small weapon systems such as artillery shells. The precision-guided munitions such as Small Diameter Bomb (SDB) of United States can be used for pinpoint strike by acquiring and tracking GNSS signals in high mobility situation. In this paper, a small GNSS receiver with embedded interference suppression capability working under high dynamic stress is developed which is applicable to the various weapon systems and can be used in other several harsh environments. It applies a kind of matched filter and multiple correlator schemes for fast signal acquisition and tracking of even weak signals and frequency domain signal processing method to eliminate the narrowband interference. To evaluate the performance of the developed GNSS receiver, the test scenario of high mobility and interference environment with the GNSS simulator and signal generator is devised. Then, the signal acquisition time, navigation accuracy, sensitivity, and interference suppression performances under high dynamic operation are evaluated. And the comparison test with the commercial GNSS receiver which has high sensitivity is made under the same test condition.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2018.11a
• /
• pp.55-58
• /
• 2018

본 논문에서는 가이디드 영상 필터를 (guided image filter) 이용하여 컨볼루션 신경망 (convolutional neural network) 을 이용한 역 톤 매핑 (inver tone - mapping; iTMO) 기법의 결과를 향상 시킬 수 있는 알고리듬을 제안한다. 기존 low dynamic range (LDR ) 영상을 high dynamic range (HDR ) 디스플레이에서 표현할 수 있는 역 톤 매핑 기법이 과거부터 계속 제안되어 왔다. 최근에 컨볼루션 신경망을 이용하여 단일 LDR 영상만으로 넓은 동적 범위 (dynamic range) 를 가진 HDR 영상으로 변환하는 알고리듬이 많이 연구되었다. 기존의 알고리듬 중 포화 영역 (saturated region) 으로 인해 잃어버린 화소 정보를 학습된 컨볼루션 신경망을 이용해서 복원하는 알고리듬은 그 효과가 좋지만 포화 영역이 아닌 부분의 잡음을 제거하지 못하며 포화 영역의 디테일을 복원하지 못한다. 제안한 알고리듬은 입력 영상에 가중치 기반 가이디드 영상 필터를 사용해서 비포화 영역의 잡음을 제거하고 포화 영역의 디테일을 복원시킨 다음 컨볼루션 신경망에 인가하여 결과 영상의 품질을 개선하였다. 제안하는 알고리듬은 실험을 통해서 기존의 알고리듬에 비해 높은 정량적 화질 평가 지수를 나타내었고, 기존의 알고리듬에 비해 세부 사항을 효과적으로 복원할 수 있음을 확인할 수 있었다.

• Journal of Periodontal and Implant Science
• /
• v.23 no.3
• /
• pp.577-594
• /
• 1993

The ultimate goal of periodontal therapy is the regeneration of the periodontium that have been destroyed as a result of periodontal disease. This study were done in order to determine the healing status of periodontium under Polytetrafluoroethylene and millipore fillter combined with fibrin and the effect of the guided tissue regeneration procedures were performed as follows : 1) flap operation using PTFE membrane(control group) 2) flap operation using PTFE membrane which was fixed with fibrin(experimental group 1) 3) flap operation using millipore filter which was fixed with suture(experimental group II) 4) flap operation using millipore filter which was fixed with fibrin(experimental group II) After 1, 2, 4, 8, 12 weeks, dogs were sacrificed by perfusion technique and tissue block was excised including the tooth and prepared for light microscope with H-E & Masson’s trichrome staining. The result were as follows : In control and experimental group, there is no siginificant difference on epithelial cell down growth within 1st week, but more epithelial cell downgrowth in millipore or millipore combined with fibrin group. In this experiment, there were no significant difference in new cementum and alveolar bone formation whether PTFE membrane was fixed with suture or fibrin. In control and each experimental group, bone maturation appeared in 4 weeks, bone width increased bucco-lingually in control and experimental 1 group especially. Both control group and experimental group showed mild mew cementum formation on root surface and irregular arrangement of collagen fiber at 4 weeks, that showed obvious increased cementum formation at 8 weeks, and that was observed the functional arrangement of collagen fiber between new cementum and new alveolar bone at 12 weeks.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.2
• /
• pp.123-128
• /
• 2014

This paper presents the study about MGV(Magnetic guidance vehicle) with up-and-down rotating type differential drive unit. Previous MGV needs the landmarks to get the driving information and additional sensor to recognize the landmarks except for localization sensor. Previous MGV requires at least 2 drive units when common fixed differential drive unit is used because it occurs the problems with driving control and localization error from imbalance of the MGV's weight. To solve such problems, we propose the MGV using up-and-down rotating type differential drive unit. Proposed MGV recognizes the driving information from the pattern which is consisted of both pole of magnet without landmarks and additional sensors, and it control the backward movement using up-and-down rotating type differential drive unit instead of common drive units. Proposed MGV considers KF(Kalman filter) to improve the localization accuracy. To verify the performance of proposed method, we designed MGV for the experiment. As the results, we can confirm the performance of propoesed method to recognize the pattern and to control the backward movement. With respect to localization, proposed method has the less RMSE about 5.6904 mm than previous method.

• Journal of Intelligence and Information Systems
• /
• v.15 no.1
• /
• pp.51-64
• /
• 2009

A location tracking sensor such as GPS, INS, Radar, and optical equipments is used in tracking Maneuvering Targets with a multi-sensor, and such systems are used to track, detect, and control UAV, guided missile, and spaceship. Until now, Most of the studies related to tracking Maneuvering Targets are on fusing multiple Radars, or adding a supplementary sensor to INS and GPS. However, A study is required to change the degree of application in fusions since the system property and error property are different from sensors. In this paper, we perform the error analysis of the sensor properties by adding a ground radar to GPS and INS for improving the tracking performance by multi-sensor fusion, and suggest the tracking algorithm that improves the precision and stability by changing the sensor probability of each sensor according to the error. For evaluation, we extract the altitude values in a simulation for the trajectory of UAV and apply the suggested algorithm to carry out the performance analysis. In this study, we change the weight of the evaluated values according to the degree of error between the navigation information of each sensor to improve the precision of navigation information, and made it possible to have a strong tracking which is not affected by external purposed environmental change and disturbance.

• Korean Journal of Pharmacognosy
• /
• v.32 no.4 s.127
• /
• pp.327-329
• /
• 2001

Cordyceps militaris (CM) has been used as a tonics in the traditional medicine. To investigate the anti-diabetic principle of CM, activity guided fractionation was conducted. Hot water extract of CM was fractionated into 3 parts: above 100,000(A), $100,000{\sim}20,000(B)$, below 20,000(C) in molecular weight using in membrane filter system. All fractions showed mild hypoglycemic activity in streptozotocin (STZ)-induced diabetic rats by oral administration (300 mg/kg). The fraction C which was most active among them was fractionated again into two parts, C-1 and C-2 by Sephadex LH 20 column chromatography. The fraction C-1 showed hypoglycemic activity but C-2 did not show activity compared with control in STZ mice. In glucose-fed hyperglycemic mice, fraction C, C-1 and C-2 also showed significant glucose lowering activity. Their decreasing rates of plasma glucose level after 1 hours administrations of fraction C, C-1 and C-2 were 24.5%, 29.3% and 22.0%, respectively (Tolbutamide: 48.4%). These results suggested that CM has both insulin like and insulin release promoting activity and could be developed as an antidiabetic agent.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.17 no.5
• /
• pp.48-54
• /
• 2018

With the 4th industry era, smart factories are emerging. In the era of multi-product small scale production, unmanned transportation vehicles are rapidly increasing in utilization of unmanned transportation vehicles that carry and arrange goods in the work space. The conventional unmanned vehicle detected its position by using the guided line method and the position based method for indoor location recognition and movement. This method has disadvantages of initial high cost and maintenance / maintenance. In this paper, to solve the disadvantages, the method of predicting the direct path of the unmanned vehicle through the Kalman filter is verified using the white LED marker of the warehouse and the position data and the image data of the white LED marker recognition image. Through this, the reliability of the linear movement which occupies the most part in the lattice structure is secured. It is also expected that the reliance on additional position sensors will also be reduced.

• Journal of the Optical Society of Korea
• /
• v.14 no.4
• /
• pp.395-402
• /
• 2010

This study reports a portable and precision photonic biosensor reader that can measure the concentration of a particular antigen using an optical resonant reflection biosensor (ORRB). To create a compact biosensor reader, a compact tunable vertical-cavity surface-emitting laser (VCSEL) and a compact built-in wavelength meter were manufactured. The wavelength stability and accuracy of the compact built-in wavelength meter were measured to be less than 0.02 nm and 0.06 nm, respectively. The tunable VCSEL emission wavelength was measured with the compact built-in wavelength meter, it has a fast sweep time (~ 10 seconds) and a wide tuning range (> 4 nm) that are sufficient for biosensor applications based on ORRB. The reflection spectrum of a plastic based ORRB chip was measured by the fabricated portable photonic biosensor reader using the VCSEL and wavelength meter. Although the reader is the size of a palmtop device, it could make a precise measurement of the peak wavelength on equal terms with a conventional bulky optical spectrometer.