• Journal of Power Electronics
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• 제16권5호
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• pp.1802-1812
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• 2016

Cross regulation is a key technical issue of single-inductor multiple-output (SIMO) DC-DC converters. This paper investigates the cross regulation in single-inductor dual-output (SIDO) Buck converters with continuous conduction mode (CCM) operation. The expressions of the DC voltage gain, control to the output transfer function, cross regulation transfer function, cross coupled transfer function and impedance transfer function of the converter are presented by the time averaging equivalent circuit approach. A small signal model of a SIDO CCM Buck converter is built to analyze this cross regulation. The laws of cross regulation with respect to various load conditions are investigated. Simulation and experiment results verify the theoretical analysis. This study will be helpful for converter design to reduce the cross regulation. In addition, a control strategy to reduce cross regulation is performed.

• 대한수학회보
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• 제43권2호
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• pp.443-459
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• 2006

The prey-predator system with a single cross-diffusion pressure is known to possess a local solution with the maximal existence time $T\;{\leq}\;{\infty}$. By obtaining the bounds of $W\array_2^1$-norms of the local solution independent of T we establish the global existence of the solution. And the long-time behaviors of the global solution are analyzed when the diffusion rates $d_1\;and\;d_2$ are sufficiently large.

• 한국안전학회지
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• 제32권6호
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• pp.143-149
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• 2017

According to traffic accidents statistics, the number of fatalities, injuries and the rate of increase of traffic accidents have been decreasing over last 5-years. The fatality rate is 1.9 for total accidents but the fatality rate for single vehicle accidents shows a 7.9, which is 4 times greater than the average for all accidents. Single vehicle accidents, usually occur as a vehicle impacts a fixed objects on the roadside as the vehicle runs-off from the road. However, few researches have been conducted considering the accident severity of single vehicle accidents which impact to the fixed objects on the road. The single vehicle accident is directly related to the composition of road cross section, (since it is the required the minimum width of a road for all run-off-the-road vehicles to recover or come to a safe stop). Therefore, this study analyzes the influence of road cross section on traffic accidents to find out the severity of single vehicle accident. To analyze the road elements which are related to the accident severity, the Ordered Probit Model was used. As variables, the element of road cross section such as the radius(m), vertical curve(%), cross sectional grade(%), road width(m). number of climbing lane, median, and curb, were used (as was the 3-years of accidents data). This study found out that cross slope(%), road width(m), and the number of climbing lane are related to the severity of accident. The result of this study could be expected to improve the road safety and to be used as the base data for further road safety research.

• 한국군사과학기술학회지
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• 제19권5호
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• pp.598-605
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• 2016

One of the effective methods for angular deception against monopulse radar is a cross eye technique. The typical cross eye technique can cause significant angular errors to monopulse radar by using two transceivers which transmit the signals with opposite phases. However, typical cross eye systems have high complexity of implementation because two transceivers should be installed with enough distance on the platform. In this paper, we propose a new cross eye technique with single transceiver based on the multipath effect. Then, angular deception performance of the proposed technique is analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.924-925
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• 2008

There are many types of grid-connected inverter controllers, PI controller based is the most popular methods. But, a common PI control is produced zero-steady state error and phase delay in sinusoidal reference. Synchronous reference frame or DQ transform based controller is capable for reducing both of zero-steady state error and phase delay is. But DQ transform based controller has cross-coupling component which difficult to analyze the system in single phase model. In this paper, to obtained single phase model of the system, DQ transform based controller is analyzed in two techniques. The first is by neglecting cross-coupling. The second is eliminated cross-coupling component by decoupling method. By these two techniques, single phase model is obtained. Then, the single phase model is analyzed to evaluate its performance in stability and frequency response, through Root Locus and Bode diagram, respectively. MATLAB and PSIM simulation is used to verify the analysis. Simulation result is shown; cross-coupling component has no significant influent to the controller.

• Mycobiology
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• 제35권4호
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• pp.230-234
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• 2007

In order to breed a Cordyceps bassiana isolate that stably forms fruiting body in artificial cultivation, isolates derived from subculturing and single spores were tested through mating. From C. bassiana EFCC 783, three subcultured isolates EFCC 2830, EFCC 2831 and EFCC 2832 were obtained and fourteen single conidial isolates were obtained from these three subcultured isolates. Two different morphological types were found in the fourteen single conidial isolates. One type was able to form synnemata and another type was not able to form synnemata. Since switch of morphological type was not observed despite their continuous subculturing, cross was performed between the two types and the formation of fruiting body was examined. Ascospores were obtained from a selected fruiting body formed by hybrid of the cross. Self-cross and combinational cross of the ascospore-derived isolates generated hybrids that stably produce high quality fruiting body in artificial media.

• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.199-205
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• 2005

When recording single-unit responses from neural systems, a common problem is the accurate detection of spikes (action potentials) in the presence of competing unwanted (noise) signals. While some sources of noise can be readily dealt with through filtering or 'template subtraction' techniques, other sources present a more difficult problem. In particular, noise components introduced by power supplies, which contain harmonics of the power-line frequency, can be particularly troublesome in that they can mimic the shape of the desired spikes. Thus, standard 'template subtraction' techniques or notch-filtering approaches are not appropriate. In this study, we propose the use of a novel template-subtraction scheme that involves estimating the power-line noise waveform and using cross-correlation techniques to subtract them from the recordings. This technique requires two key steps: (1) cross-correlation analysis of each recorded waveform extracts a robust representation of the power-line noise waveform and (2) a second level of cross-correlation to successfully subtract that representation from each recorded waveform. This paper describes this algorithm and provides examples of its implementation using actual recorded waveforms that are contaminated with these noise signals. An improvement (reduction) in the noise level is reported, as are suggestions for future implementation of this strategy.

• Wind and Structures
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• 제11권3호
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• pp.221-240
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• 2008

The spanwise flow structure around a rigid smooth circular cylinder model in cross-flow has been investigated based on the experimental data obtained from a series of wind tunnel tests. Surface pressures were collected at five spanwise locations along the cylinder over a Reynolds number range of $1.14{\times}15^5$ to $5.85{\times}10^5$, which covered sub-critical, single-bubble and two-bubble regimes in the critical range. Separation angles were deduced from curve fitted to the surface pressure data. In addition, spanwise correlations and power spectra analyses were employed to study the spatial structure of flow. Results at different spanwise locations show that the transition into single-bubble and two-bubble regimes could occur at marginally different Reynolds numbers which expresses the presence of overlap regions in between the single-bubble regime and its former and later regimes. This indicates the existence of three-dimensional flow around the circular cylinder in cross-flow, which is also supported by the observed cell-like surface pressure patterns. Relatively strong spanwise correlation of the flow characteristics is observed before each transition within the critical regime, or formation of first and second separation-bubbles. It is also noted that these organized flow structures might lead to greater overall aerodynamic forces on a circular cylinder in cross-flow within the critical Reynolds number regime.

• 항공우주시스템공학회지
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• 제12권6호
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• pp.41-49
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• 2018

이번 연구에서는 복합재료 박벽보(thin-walled beam)에서 시위 방향으로 단일 셀의 비대칭성 단면을 가지는 모델을 선정하여, 단면의 형상에 대한 이론적인 동특성을 연구하였다. 이를 위해 전단 변형 효과(transverse shear effect)와 와핑 구속 효과(warping restraint effect), 보의 길이 방향으로 일정한 테이퍼비와 기하학적 단면비 등을 고려하고, 비대칭 단면의 와핑 함수 보정을 통해 수학적 모델링을 수행하였다. 그 결과에 따라, 고려한 단면의 질량 계수와 강성 계수 및 고유 진동수 등의 특성을 조사하였다. 특히, 단면의 비대칭성, 와핑 함수를 보정하지 않은 경우, 모델의 테이퍼비와 단면비 등이 고유 진동수에 미치는 영향을 비교 분석하였다.

• Archives of Plastic Surgery
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• 제50권5호
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• pp.507-513
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• 2023

Background Free tissue transfer is considered the gold standard option for the reconstruction of distal leg defects. Free tissue transfer using recipient vessels in the contralateral leg (cross-leg bridge) is a potential option to supply the flap if there are no suitable recipient vessels in the injured leg. Most studies have described this technique using end-to-end anastomosis which sacrifices the main vessel in the uninjured leg. This study evaluated the use of a cross-leg free latissimus dorsi muscle flap for the reconstruction of defects in single-vessel legs, using end-to-side anastomosis to recipient vessels in the contralateral leg without sacrificing any vessel in the uninjured leg. Methods This is a retrospective study that included 22 consecutive patients with soft tissue defects over the lower leg. All the reconstructed legs had a single artery as documented by CT angiography. All patients underwent cross-leg free latissimus dorsi muscle flap using end-to-side anastomosis to the posterior tibial vessels of the contralateral leg. Results The age at surgery ranged from 12 to 31 years and the mean defect size was 86 cm². Complete flap survival occurred in 20 cases (91%). One patient had total flap ischemia. Another patient had distal flap ischemia. Conclusion Cross-leg free latissimus dorsi muscle flap is a reliable and safe technique for the reconstruction and salvage of mutilating leg injuries, especially in cases of leg injuries with a single artery. As far as preservation of the donor limb circulation is concerned, end-to-side anastomosis is a reasonable option as it maintains the continuity of the donor leg vessels.