• Journal of Korea Society of Industrial Information Systems
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• v.17 no.4
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• pp.61-70
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• 2012

We propose a method that finds candidate targets based on morphology and detects a small target from them using modified gaussian distance function. The existing small target detection methods use predictive filters or morphology. The methods using predictive filters take long to approach least errors. The methods using morphology are weak at clutters and need to consider size of a small target when selecting size of structure elements. We propose a robust method for small target detection to complete the existing methods. First, the proposed method deletes clutters using a median filter. Next, it does closing and opening operation using various size of structure elements, and figures target candidate pixels with subtraction operation between the results of closing and opening operation. It detects an exact small target using a gaussian distance function from the candidates target areas. The proposed method is less sensitive to clutters, and shows a detection rate of 98%.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.114-120
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• 1991

In electron therapy, low melting point alloy is used for shaping of the field. Electron field shaping material affect the output factor as well as the collimator system. The output factors of electron beams for shaped fields from NELAC-1018 were measured using ionization chamber of Farmer type in water phantom. The output factors of electron beams depend on the incident energy, inherent collimator system and the size of shaped field. Obtained results were followings. 1. In the smaller applicator, output varied extremely according to extent of collimator opening. 2. The higher energy, the output is less varied according to treatment field at small field.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1991.06a
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• pp.15-15
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• 1991

한국어 자음에 대한 생리적인 분류는 조음점 및 조음발법에 따라 다시 세분화할 수 있는데 그중에서 조음발법에 따라 파열음, 마찰음, 파찰음 및 비음들 여러가지로 분류할 수 있다. 그중 특히 파열음은 그 개방하는 방법에 따라 연음(lenis), 경음(glottalized) 및 기식음(aspirated)등으로 구분하는데 이러한 각음을 육안으로 확인하면 모음이 발성되기 위한 성대진동이 있기전의 자음을 위한 성대의 운동의 현상을 보면 기식음에서는 성대열림이 가장 크고 연음에서도 열림이 크지만 기식음보다는 적고 경음에서는 성대의 열림이 가장 작았다. 이러한 현상은 후두내시경에 의해 쉽게 확인할 수 있었는데 이것을 과학적으로 규명하기 위해서는 여러연구에 의해 가능하나 흔히 후두근전도 검사에 의한 성대내전근과 외전근의 역할의 차이를 비교함으로서 가능해지리라 예상되어 본 연구를 시행하였다. 사용된 문형 또는 단어는 한가지를 제외하고는 모두 의미있는 단어를 사용하였으며 EMG recording을 위해 사용된 근육은 후두내전근인 Vocalis muscle과 후두외전근인 Posterior cricoarytenoid muscle이 사용되었고 전기신호는 computer data processing system에 의해 분석되어졌다. 결과는 내시경에 의한 성대열림의 거리측정 결과를 분석함과 동시에 후두내근에 대한 근전도검사에 의한 분석을 토대로 하였으며 이를 간단히 설명하면 이제까지 많은 사람들은 한국어 자음에 대한 각각의 특징적인 현상들을 주로 성대내전근의 역할에 의해 규명하였으나 본 결과로는 성대내전근의 역할도 중요하지만 성대외전근의 역할 또한 상호 연관성을 가지면서 매우 중요한 역할을 한다는 점이다.for the Isotropic plates can be used. Use of some coefficients can produce "exact" value for laminates with such configuration.trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation energy of carriers from the shallo

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.8 no.3
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• pp.13-22
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• 2012

According to recent research on leak-rate estimates to assess rupture probabilities of nuclear piping which contains a circumferential surface/through-wall cracks due to PWSCC, i.e., xLPR (Extremely Low Probability of Rupture) program, it has been revealed that the use of crack shape with an idealized circumferential through-wall crack during actual crack growth can lead to overestimate of the leak-rate. Thus, for accurate estimation of the leak-rate during crack growth, the more realistic crack shape that can simulate the crack shape transition from surface crack to through-wall crack should be used. In this context, in the present study, the elastic crack opening displacement of slanted circumferential through-wall crack in thick-walled cylinder was proposed based on 3-dimensional elastic finite element fracture mechanics analyses. To propose the elastic crack opening displacement of slanted circumferential through-wall crack in thick-walled cylinder, the geometric variables affecting crack opening displacement, i.e., thickness of cylinder, reference inner crack length and slant crack ratio were systematically varied. In terms of loading conditions, axial tension, global bending moment and internal pressure were considered. The present results can be applied to calculate the leak-rate considering more realistic crack shape transition from surface crack to idealized through-wall crack, and can be expected to enhance current leak-rate estimation scheme, for instance, in xLPR program etc.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.3
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• pp.151-165
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• 2021

Grouting, which is applied for the increase of ground strength and the decrease of permeability, is complex process because of several reasons, so the process needs to be elaborated. Injection process in consideration of ground condition and optimization of grouting sequence is essential. In this study, GIN (Grouting Intensity Number), multiple of injected grout volume and pressure, is revised to consider injection pressure reduction and joint opening during grouting process. A revised GIN process is evaluated through a field test. A revised GIN, considering ground condition, injection pressure, follows GIN envelope and produces rational grouting process. The result of a revised GIN reduces permeability of the ground in the order of 10^-1~10^-2 cm/sec.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.390-395
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• 2004

In order to characterize ion channels present in tomato roots, microsomes were incorporated into an artificial lipid bilayer arranged for electrophysiological analysis. Of the five different ion channels that could be found, a channel of 450 pS conductance was found most frequently. This channel displayed subconductance states of 450, 257 and 105 pS. All subconductance states showed linear current-voltage relationships. At positive holding potentials, high frequency of transient channel openings was observed; however, at negative potentials, the open times were long and open probability high. Po was 0.83 at -40 mV. When an additional 50 mM $K^+\;or\;Na^+$ was added to the cis side of bilayer, the reversal potentials shifted in the negative direction to near -10 mV. Thus, the 450 pS cation channel selects poorly between $K^+\;and\;Na^+$. In the presence of $100\;{\mu}M$ metal ions, the channel activity was severely inhibited by $La^{3+},\;Ba^{2+},\;and\;Zn^{2+}$, and Po was decreased to 0.2 or even less. However, $Al^{3+}\;and\;Cd^{2+}$ decreased the activity by only 20%. Interestingly, each metal ion showed different kinetics of channel inhibition. While $500\;{\mu}M\;La^{3+}$ inhibited the activities of all subconductance state, 1 mM $Zn^{2+}$ inhibited all except the 105 pS state. $Cd^{2+}$ changed the gating of the channel from a long-opening state to brief transient openings even at negative holding potentials. These data represent that the metal ions may have different binding sites on the channel protein and could be useful modulators and probes to investigate structural characteristics as well as the functional roles of the 450 pS channel on the root physiology.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.4
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• pp.479-488
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• 2002

In recent years the amount of digital video used has risen dramatically to keep pace with the increasing use of the Internet and consequently an automated method is needed for indexing digital video databases. Textual information, both superimposed and embedded scene texts, appearing in a digital video can be a crucial clue for helping the video indexing. In this paper, a new method is presented to extract both superimposed and embedded scene texts in a freeze-frame of news video. The algorithm is summarized in the following three steps. For the first step, a color image is converted into a gray-level image and applies contrast stretching to enhance the contrast of the input image. Then, a modified local adaptive thresholding is applied to the contrast-stretched image. The second step is divided into three processes: eliminating text-like components by applying erosion, dilation, and (OpenClose+CloseOpen)/2 morphological operations, maintaining text components using (OpenClose+CloseOpen)/2 operation with a new Geo-correction method, and subtracting two result images for eliminating false-positive components further. In the third filtering step, the characteristics of each component such as the ratio of the number of pixels in each candidate component to the number of its boundary pixels and the ratio of the minor to the major axis of each bounding box are used. Acceptable results have been obtained using the proposed method on 300 news images with a recognition rate of 93.6%. Also, my method indicates a good performance on all the various kinds of images by adjusting the size of the structuring element.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.3
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• pp.87-95
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• 2005

Most of the motorcycle engines have used carburetors in the fuel system, because of its simple structure and reliability but the fuel economy and the emissions of those engines are bad when we compared with automobile engines .To meet with the tighten emission regulations and the higher requirements for fuel economy, the application of the carburetor on the motorcycle engines would be limited. Therefore, it is important to develope a ECU control system for motorcycle engines. Since the fuel injection system is expensive, it is necessary to decrease the cost of ECU system for motorcycle engines, but the accuracy of the ECU control system should be increased as high as possible. In this paper, we studied about the AFS characteristics of motorcycle engine controled by indirect method.

• Computational Structural Engineering
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• v.3 no.4
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• pp.113-122
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• 1990

An analytical simulation of the flexural behavior of SFRC beam has been illustrated. Curvature distributions and crack opening in critical region were taken into account. Compressive and tensile constitutive models which express post-peak behavior of SFRC with stress-crack opening relationships were incorporated in simulating nonlinear flexural behavior of the beam. The model was able to predict test results with reasonable accuracy. Behavior of the critical section and effects of different factors m the flexural behavior of SFRC beam were investigated. Simple observation and statistical approach have been made in selecting most influential parameters in flexural behavior of SFRC.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.378-385
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• 2000

Fracture resistance (J-R) curves, which are used for elastic-plastic fracture mechanics analyses, decreased under tension-compression loading condition. This phenomenon was proved by several former researches, but the causes have not been clear yet. The objective of this paper is to investigate the cause of this phenomenon. On the basis of fracture resistance curve test results, strain hardening hypothesis, stress redistribution hypothesis and crack opening hypothesis were built. In this study, hardness tests, Automated Ball Indentation(ABI) tests, theoretical stress field analyses, and crack opening analyses were performed to prove the hypotheses. From this study, strain-hardening of material, generation of tensile residual stress at crack tip, and crack opening effects are proved as the causes of the decrease hypothesis.