• The Korean Journal of Physiology
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• v.26 no.1
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• pp.15-25
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• 1992

In order to elucidate the properties of the background current whole cell patch clamp studies were performed in rabbit ventricular cells. Ramp pulses of ${\pm}80\;mV$ from holding potential of 40 mV(or 20 mV) at the speed of 0.8 V/sec were given every 30 sec(or 10 sec) and current-voltage diagrams(I-V curve) were obtained. For the activation of the background current isoprenaline, adenosine 3',5'-cyclic monophosphate(dBcAMP), guanosine 3',5'-cyclic monophosphate(cGMP), and $N^6$-2'-o-dibutyryladenosine 3',5'-cyclic monophosphate(dBcAMP) were applied after all known current systems were blocked with 2mM Ba, 1 mM Cd ,5 mM Ni, 10 ${\mu}M$ diltiazem, 10 ${\mu}m$ ouabain, and 20 mM tetraethylammonium(TEA). The conductance of background current in control was $0.65{\pm}0.69$ nS at 0 mV, its I-V curves was almost linear and reversed near 50 mV. When there was no taurine in pipette solution, isoprenaline hardly activated the background current but when taurine existed in pipette solution, isoprenaline activated the larger background current. Cyclic AMP or cyclic GMP alone had little effect on the activation of the background current, while cGMP potentiated cGMP effect. When the background current was activated with cGMP and cAMP, isoprenaline could not further increased the background current. The background current activated by isoprenaline depended on extracellular $Cl^-$ concentration and its reversal potential was shifted according to chloride equilibrium potential. The change of extracellular $Na+$ concentration had little effect on reversal potential of the background current activated by isoprenaline.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06c
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• pp.477-481
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• 2007

A background is a part where do not vary too much or frequently change in an image sequence. Using this assumption, it is presented a background acquisition algorithm for not only static but also dynamic view in this paper. For generating background, we detect a region, where has high correlation rate compared within selected region in the prior pyramid image, from the searching region in the current image. Between a detected region in the current image and a selected region in the prior image, we calculate movement vector for each regions in time sequence. After we calculate whole movement vectors for two successive images, vector histogram is used to determine the camera movement. The vector which has the highest density in the histogram is determined a camera movement. Using determined camera movement, we classify clusters based on pixel intensities which pixels are matched with prior pixels following camera movement. Finally we eliminate clusters which have lower weight than threshold, and combine remained clusters for each pixel to generate multiple background clusters. Experimental results show that we can automatically detect background whether camera move or not.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.159-161
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• 2004

Many motion object detection algorithms rely on the process of background subtraction, an important technique that is used for detecting changes from a model of the background scene. This paper propose a novel method to update the background model image of a visual surveillance system which is not stationary. In order to do this, we use a background model based on statistical qualities of monitored images and another background model that excluded motions. By comparing each changed area computed from the two background model images and current monitored image, the areas that will be updated are decided.

• The Korean Journal of Physiology
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• v.26 no.2
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• pp.99-111
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• 1992

Permissive action of thyroid hormone at the level of Ca channel and responsible mechanisms underlying thyroid hormone-induced change in myocardial contractile state and $T_3-induced$ arrhythmias were investigated in rabbit ventricular or atrial myocytes using whole cell patch clamp technique. Single cells were isolated by Langendorff perfusion with collagenase. Cardiac myocytes were incubated in $low-Cl^-,$, $high-K^+$ medium containing $1_{\mu}M\;L-triiodothyronine\;(T_3)$ at $4^{\circ}C$ for 2.10 hours. The calcium currrent $(I_{Ca})$ was increased in $T_3$ loaded cells, however, the shape of current voltage curve and reverse potential did not altered. Cyclic AMP, cyclic GMP, isoprenaline and 3-isobutyl-1-methyl-xanthine increased $I_{Ca}$ in euthyroid and hyperthyroid conditions, and acetylcholine blocked the increase of $I_{Ca}\;in\;T_3$ loaded cells. The amplitude of $I_{Ca}$ was much larger after perfusing cGMP than cGMP in both conditions, whereas the degree of increase of $I_{Ca}$ was greater after perfusing cAMP than cGMP in $T_3$ loaded cells. The degree of increase of $I_{Ca}$ after perfusing isoprenaline or IBMX also was greater in $T_3$ loaded cells than in control cells. Background current induced by isoprenaline also increased in $T_3$ loaded cells. The Ca release dependent inward current was increased in amplitude but its activation and inactivation time course was not changed in $T_3$ loaded cells. Activation of Na pump current was not changed in $T_3$ loaded cells. From the above results it is suggested that thyroid hormone induced increase in the contractile state of cardiac myocytes are accompanied by augmented $I_{Ca}$ and the increase of Ca release from sarcoplasmic reticulum and the permissive action of thyroid hormone to catecholamines could induce arrhythmias through the increase of $I_{Ca}$ and background current.

• Journal of information and communication convergence engineering
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• v.12 no.3
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• pp.193-197
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• 2014

Edges are a robust feature for object detection. In this paper, we present an edge-based background modeling method for the detection of moving objects. The edges in the image frames were mapped using robust Canny edge detector. Two edge maps were created and combined to calculate the ultimate moving-edge map. By selecting all the edge pixels of the current frame above the defined threshold of the ultimate moving edges, a temporary background-edge map was created. If the frequencies of the temporary background edge pixels for several frames were above the threshold, then those edge pixels were treated as background edge pixels. We conducted a performance comparison with previous works. The existing edge-based moving-object detection algorithms pose some difficulty due to the changes in background motion, object shape, illumination variation, and noises. The result of the performance evaluation shows that the proposed algorithm can detect moving objects efficiently in real-world scenarios.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.11-18
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• 2007

A moving object detection algorithm for surveillance video is here proposed which employs background initialization based on two-stage median filtering and a background updating method based on state transition diagram. In the background initialization, the spatiotemporal similarity is measured in the subinterval. From the accumulated difference between the base frame and the other frames in a subinterval, the regions affected by moving objects are located. The median is applied over the subsequence in the subinterval in which regions share similarity. The outputs from each subinterval are filtered by a two-stage median filter. The background of every frame is updated by the suggested state transition diagram The object is detected by the difference between the current frame and the updated background. The proposed method showed good results even for busy, crowded sequences which included moving objects from the first frame.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.140-141
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• 2006

Background doping concentration (BDC) is proven to be a critical factor to affect the high current behavior of the extended drain NMOSFET (EDNMOS) devices. The EDNMOS device with low BDC suffers from strong snapback in the high current region, which results in poor electrostatic discharge (ESD) protection performance and high latchup risk. However, the strong snapback can be avoided in the EDNMOS device with high BDC. This implies that both the good ESD protection performance and the latchup immunity can be realized in terms of the EDNMOS by properly controlling its BDC.

• Archives of Plastic Surgery
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• v.50 no.1
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• pp.96-100
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• 2023

The microsurgical anastomosis is integral to the success of autologous-free tissue transfer. Successful performance of this procedure relies strongly on operator dexterity, which can be made more challenging when blood and edematous fluids obscure the field of view. Workflow is impeded by intermittent irrigation and suctioning, necessitating presence of an assistant, with risk of arterial thrombosis, from vessels being drawn into suction drains. To negate these current disadvantages and minimize the barrier of entry to microvascular operations, we designed, manufactured, and patented a novel three-dimensional printed microsurgical background device with microfluidic capabilities that allow continuous suction and irrigation as well as provide platforms that enable multiangle retraction to facilitate operator autonomy. This was validated in an ex vivo model, with the device found to be superior to the current standard. We believe that this will have major applicability to the improvement of microsurgeon

• The Mathematical Education
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• v.55 no.2
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• pp.233-249
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• 2016

In this study, we extracted the background meaning of the condition that four points lie on a circle, analyzed textbooks critically and proposed the orientation to improve the content in the textbook. As results, the condition has a realistic background meaning which is 'mathematical modeling of finding a fair location'. The condition has a mathematical background meanings which are 'a first complex situation distinguished from two points and three points', 'the condition described in the perspective of side and angle in order to overcome the disadvantages of the perpendicular bisectors context' and 'being possible to transfer more than five points'. However it is difficult to understand the reason why the condition is on four points in the current textbook. In addition, it is difficult to recognize the connectivity of a circumcenter of triangle. To overcome these problems, we proposed five orientations to improve the content in the textbook.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.631-636
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• 2009

Foreground segmentation methods have steadily been researched in the field of computer vision. Especially, background subtraction which extracts a foreground image from the difference between the current frame and a reference image, called as "background image" have been widely used for a variety of real-time applications because of low computation and high-quality. However, if the background scene was dynamically changed, the background subtraction causes lots of errors. In this paper, we propose an efficient background subtraction method in dynamic environment with both static and dynamic scene. The proposed method is a hybrid method that uses the conventional background subtraction for static scene and depth information for dynamic scene. Its validity and efficiency are verified by demonstration in dynamic environment, where a video projector projects various images in the background.