• 대한임베디드공학회논문지
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• 제11권5호
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• pp.277-285
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• 2016

Moving object detection system has been an emerging research field in various advanced driver assistance systems (ADAS) and surveillance system. In this paper, we propose two optical flow based moving object detection methods at dynamic scenes. Both proposed methods consist of three successive steps; pre-processing, foreground segmentation, and post-processing steps. Two proposed methods have the same pre-processing and post-processing steps, but different foreground segmentation step. Pre-processing calculates mainly optical flow map of which each pixel has the amplitude of motion vector. Dense optical flows are estimated by using Farneback technique, and the amplitude of the motion normalized into the range from 0 to 255 is assigned to each pixel of optical flow map. In the foreground segmentation step, moving object and background are classified by using the optical flow map. Here, we proposed two algorithms. One is Gaussian mixture model (GMM) based background subtraction, which is applied on optical map. Another is adaptive thresholding based foreground segmentation, which classifies each pixel into object and background by updating threshold value column by column. Through the simulations, we show that both optical flow based methods can achieve good enough object detection performances in dynamic scenes.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권3호
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• pp.166-173
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• 2009

The reliability of hafnium oxide gate dielectrics incorporating lanthanum (La) is investigated. nMOSFETs with metal/La-doped high-k dielectric stack show lower $V_{th}$ and $I_{gate}$, which is attributed to the dipole formation at the high-k/$SiO_2$ interface. The reliability results well correlate with the dipole model. Due to lower trapping efficiency, the La-doping of the high-k gate stacks can provide better PBTI immunity, as well as lower charge trapping compared to the control HfSiO stacks. While the devices with La show better immunity to positive bias temperature instability (PBTI) under normal operating conditions, the threshold voltage shift (${\Delta}V_{th}$) at high field PBTI is significant. The results of a transconductance shift (${\Delta}G_m$) that traps are easily generated during high field stress because the La weakens atomic bonding in the interface layer.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.430-432
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• 2008

Visible channel calibration method using deep convective clouds (DCCs) is developed. The method has advantages that visible radiance is not sensitive to cloud optical thickness (COT) for deep convective clouds because visible radiance no longer increases when COT exceeds 100. Therefore, once DCCs are chosen appropriately, and then cloud optical properties can be assumed without operational ancillary data for the specification of cloud conditions in radiative transfer model. In this study, it is investigated whether IR measurements can be used for the selection of DCC targets. To construct appropriate threshold value for the selection of DCCs, the statistics of cloud optical properties are collected with MODIS measurements. When MODIS brightness temperature (TB) at 11 ${\mu}$ m is restricted to be less than 190 K, it is shown that more than 85% of selected pixels show COT ${\geq}$ 100. Moreover, effective radius ($r_e$) distribution shows a sharp peak around 20 ${\mu}m$. Based on those MODIS observations, cloud optical properties are assumed as COT = 200 and $r_e$ = 20 ${\mu}m$ for the simulation of MODIS visible (0.646 ${\mu}m$) band radiances over DCC targets.

• Journal of the Korean Wood Science and Technology
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• 제27권4호
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• pp.43-50
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• 1999

The safety-evaluation of ancient wood structures has been executed with only visual inspection. The application of NDE(nondestructive evaluation) is required because the visual inspection has many restrictions. Among many NDE techniques, the stress wave technique was used in this research. This study focused on evaluating the extent of decay in members of ancient structures, using stress wave nondestructive technique. For application of stress wave technique to ancient structures, the threshold time which divides members into categories according to degree of decay should be determined in advance. Stress wave timer (Metriguard Model 239A) was used in this study, specimens used in this research were the members obtained from six ancient structures. All specimens were identified as Hard Pine(Pinus densiflora S. et Z. or Pinus thunbergii P.) by microscope. Each member was tested with stress wave passing radially through the pith. In this study, the stress wave time of $12{\mu}s$/cm could distinguish between sound and decayed specimens with accuracy of 77.5 percent. Also, decayed specimens could be separated into moderate and severe categories by stress wave time of $20{\mu}s$/cm. Among the three decay location groups (exterior, mixed, interior), the exterior group could be classified into sound, moderate and severe decay with the greatest accuracy. Stress wave transit time was not sensitive to small decay pockets located in interior of the member.

• 한국식품조리과학회지
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• 제12권3호
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• pp.305-311
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• 1996

This study was to seek menu model in usual dishes to guarantee the optimum salt intake considering the optimum gustation of salt surveyed on Korean adults. First, a pilot test was practiced using rice gruel to determine the criteria and a meaningful interval of salt concentration. Based on the criteria and interval so determined, a test was performed to seek the optimum gustation of salt concentration in usual diets. Subjectgroup for the above tests was university students living in Kyung-Book area. The results were as follows: 1. Mode value of the optimum gustation of salt was 0.5% and the received threshold difference of salt was 0.2% in the pilot test. 2. Mode values of the optimum gustation of salt in a la carte, soups and stews were lower than those of other side dishes. 3. But the portion size of a la carte, soups and stews is much larger than that of other side dishes, so that a la carte, soups and stews are sources of relatively larger amount of salt than other side dishes. 4. Considering the recommended optimum salt intake, it is desirable to reduce the amount of stock in soups and stews and to select fried food or salad more frequently.

• KDI Journal of Economic Policy
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• 제33권2호
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• pp.145-175
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• 2011

본 논문은 경제적 불평등이 정치적 의사결정과정을 통하여 환경정책과 재분배 정책에 어떻게 영향을 미치는지를 분석하고 있다. 정치과정을 배제한 경제적 균형에서는 환경정책(배출세)의 도입이 미도입시와 비교하여 경제성장률의 상승을 가져올 수 있지만 그 효과에 불확실성이 존재함을 보이고 있다. 이와 달리 정치경제적 균형에서는 경제적 불평등도의 변화에 따라 환경정책과 재분배정책의 선택이 달라지는 것을 보이고, 그러한 정책 선택이 경제성장에 미치는 영향을 분석하고 있다. 보다 구체적으로 경제적 불평등도가 일정 수준으로 개선되어야 환경정책이 도입되고, 환경정책의 도입은 보다 강화된 재분배정책의 요구로 이어져 단기적으로 경제성장에 부정적인 영향을 줄 수 있음을 보이고 있다. 본 논문에서는 이러한 정치경제적 분석을 기초로 정책적 함의를 논의하고 있다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권6호
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• pp.832-841
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• 2016

The voltage-frequency island (VFI) design paradigm has strong potential for achieving high energy efficiency in communication centric manycore system-on-chip (SoC) design called network-on-chip (NoC). However, because of the diminished scaling of wire-dimension and supply voltage as well as threshold voltage in modern CMOS technology, the vulnerability to link failure in VFI NoC is becoming a crucial challenge. In this paper, we propose an energy-optimized topology generation technique for VFI NoC to cope with permanent link failures. Based on the energy consumption model, we exploit the on-chip communication traffic patterns and characteristics of link failures in the early design stage to accommodate diverse applications and architectures. Experimental results using a number of multimedia application benchmarks show the effectiveness of the proposed three-step custom topology generation method in terms of energy consumption and latency without any degradation in the fault coverage metric.

• 한국안전학회지
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• 제6권4호
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• pp.81-87
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• 1991

We propose the crack growth rate equation which will model fatigue crack growth rate behavior such that constant stress amplitude fatigue crack growth behavior can be predicted. Constant stress amplitude fatigue tests are conducted for four materials under three stress ratios of R＝0.2, R＝0.4 and R＝0.6. Materials which have different mechanical properties i.e. stainless steel, low carbon steel, medium carbon steel and aluminum alloy are used. Through constant stress amplitude fatigue test by using unloading elastic compliance method, it is confirmed that crack closure is a close relationship with fatigue crack propagation. We describe simply fatigue crack propagation behavior as a function of the effective stress intensity factor range ($\Delta$ $K_{eff}$＝U .$\Delta$K) for all three regions (threshold region, stable region). The fatigue crack growth rate equation is given by da / dN＝A($\Delta$ $K_{eff}$­$\Delta$ $K_{o}$ )$^{m}$ / ($\Delta$ $K_{eff}$­$\Delta$K) Where, A and m are material constants, and $\Delta$ $K_{o}$ is stress intensity factor range at low $\Delta$K region. $K_{cf}$ is critical fatigue stress intensity factor.actor.

• 대한간호학회지
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• 제34권5호
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• pp.722-728
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• 2004

Purpose: This study was designed to determine the predictors of postpartum depression. Method: One hundred-sixty one women within one year after delivery from one public health center located in the northern area of Seoul were used in this study. The instruments were a survey of general characteristics, the Edinburgh Postnatal Depression Scale, recent life events index, perceived social support from family, Quality of marriage index, parenting stress index, and Rosenberg's self-esteem inventory. Data was analysed using descriptive statistics, Pearson correlation coefficients, and logistic regression. Result: The average item score of the EPDS was 6.67. 12.4% of respondents, who scored above a threshold 12, were likely to be suffering from a depression of varying severity. The fitness of the model for explaining postpartum depression from six variables, plan for pregnancy, family support, quality of marital relation, perceived social support, life events, childcare stress, and self-esteem, was statistically significant and the predictive power of these variables was 90.9%. The significant predictors of postpartum depression were family support and child care stress. Conclusion: Further research is needed to identify the prevalence rate of postpartum depression using more reliable sampling methods from a large general population. Nursing interventions need to be developed for promoting family support and reducing childcare stress.

• 한국항행학회논문지
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• 제14권2호
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• pp.284-288
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• 2010

비디오 감시 장치는 사회안전망 구축분야에서 다양하게 응용되고 있다. 본 논문은 고정 카메라에서 취득된 시각정보를 이용한 침입 탐지 알고리즘을 제안하였다. 제안한 알고리즘은 비디오 시퀀스에서 AMF를 이용하여 모델링된 배경으로부터 물체 프레임 후보를 찾아내고, 감지된 물체는 움직임 정보의 분석으로 계산된다. 움직임 검출은 RGB 공간에서 2D 물체의 상대적 크기로 결정하였으며 물체 감지를 위한 임계값은 실험적인 방법으로 결정하였다. 실험 결과, 시 공간적 후보 정보들이 급격히 변화할 때, 물체 감지의 성능이 우수함을 확인할 수 있었다.