• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.310-310
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• 2011

Morphological evolution of amorphous carbon film is investigated by molecular dynamics simulation. Here, energetic carbon atoms (75 eV) are deposited on the diamond (001) substrate to find effect of incidence angles. At normal and near-normal incidences ($0^{\circ}{\sim}30^{\circ}$) atomically smooth surfaces are observed during their growth. However, rough surfaces emerge and develop into a ripple structure at grazing incidences ($60^{\circ}{\sim}70^{\circ}$). The different growth modes according to the incidence angles can be described by impact-induced displacements of atoms. Downhill transport along any sloped surfaces is predominant for the case of normal incidence. As the incidence angles become grazing, uphill transport is allowed along the surfaces, which have smaller slopes than incidence angle, so the surface features can be amplified. Impact-induced transport and self-shadowing effect can be responsible to the initial growth of seeding structures at a grazing incidence, which would be grown up as tilted columnar structures in further depositions.

• Journal of the Optical Society of Korea
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• v.20 no.2
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• pp.263-268
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• 2016

Broadband metal-dielectric-metal terahertz filters composed of complementary rings are designed and demonstrated. Four samples with different parameters were fabricated. Results measured using THz time-domain spectroscopy system show excellent agreement with simulations. Compared with the broadband filters reported before, the complementary ring structure in our design is insensitive to any polarization at normal incidence due to symmetry of the ring. Furthermore, the influence of structure parameters (such as period, radius, slot width, thickness and incidence angles) on the transmission characteristics has been investigated theoretically. The encouraging results afforded by designing of the filters could find applications in broadband sensors, terahertz communication systems, and other emerging terahertz technologies.

• Journal of the Korean Operations Research and Management Science Society
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• v.16 no.2
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• pp.128-147
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• 1991

We propose a dynamic incidence matrix (DIM) for reflecting states and time conditions of a timed Petri net (TPN) explicitly. Since a DIM consists of a conventional incidence matrix, two time-related vectors and two state-related vectors, we can get the advantages inherent in the conventional incidence matrix of describing a static structure of a system as well as another advantage of expressing time dependent state transitions. We introduce an algorithm providing the DIM with a state transition mechanism. Because the algorithm is, in fact, an algorithmic model for discrete event simulation of TPN models, we provide a theoretical basis of model transformation of a TPN model into a DEVS(Discrete Event system Specification) model. By executing the algorithm we can carry out performance analysis of computer communication protocols which are represented TPN models.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.4 no.1
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• pp.59-69
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• 1998

The purpose of this research is to be grasp the relation between lumbago incidence rate and research hypothesis in the effects of sex life of the middle-aged couples in Taejon area upon lumbago. This writer had questionaired the 400 middle-aged couples in Taejon city - Jung-gu, Seo-gu, Dong-gu, Yuseong-gu, and Taedeok-gu - from June 1, to June 30, 1998. Of them, total 209 question papers were drawn back; male 102, female 107. Analysis of the data is as follows; 1. 145(69.37%) subjects of total 209 had low back pain experience after their sexual lives. 2. In the number of sexual times a week, low back pain incidence were the most rate in 1-2 times as 41.55%, each other had a statistically significant relation (P<0.01). 3. In age and lumbago incidence rate, the 30s was 37.75% and each other had a significant relation (P<0.05). 4. In weight and lumbago incidence rate, the level of 50kg~60kg was highest and each other didn't have a significant relation (P>0.05). 5. In the mean sexual time, the period of 11~20 minutes was 29.47% and each other had a significant relation (P>0.01). 6. In a day time of sexual life and lumbago incidence rate, midnight was the highest rate(36.23%) and each other didn't have a significant relation (P>0.05). 7. In the lumbago incidence rate according to bedroom structure of sexual life, a bed was 38.17% and each other had a significant relation (P>0.05). 8. In the lumbago incidence rate according to sexual posture, a normal position showed the highest rate(46.12%) and each other didn't have a significant relation (P>0.05). According to the results of our research, lumbago has relation to the number of sex life a week, age, the mean time of sexual life, and bedroom structure of sexual life. So it is thought that it is necessary that middle-aged couples periodically study the educational programs to make an prevention education for low back pain the key points.

• Journal of Mechanical Science and Technology
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• v.18 no.2
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• pp.272-285
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• 2004

The losses at off-design points from a compressor cascade occur due to the deviation from a design incidence angle at the inlet of the cascade. The self-noise from the blade cascade at off-design points comes from a separated boundary layer and vortex sheddings. If the incidence angle to the cascade increases, stalling in blades may occur and the noise level increases significantly. This study applied Large-Eddy Simulations (LES) using deductive and deductive dynamic SGS models to low Mach-number, turbulent flow with each incidence angle to the cascade ranging from -40$^{\circ}$ to +20$^{\circ}$ and compared numerical predictions with measured data. It was observed that the oscillating separation bubbles attached to the suction surface do not modify wake flows dynamically for cases of negative incidence angles. However, an incidence angle greater than 8$^{\circ}$ caused a separated vortex near the leading edge to be shed downstream and created stalling. The computed performance parameters such as drag coefficient and total pressure loss coefficient showed good agreement with experimental results. Noise from the cascade of the compressor is summarized as sound generated by a structure interacting with unsteady, turbulent flows. The hybrid method using acoustic analogy was observed to closely predict the measured overall sound powers and directivity patterns at design and off-design points of blade cascade.

• Structural Engineering and Mechanics
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• v.63 no.5
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• pp.647-657
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• 2017

To achieve this goal, two four-span concrete box-girder bridges with typical configurations of California highway bridges are selected as representative bridges: an integral abutment bridge and a seat-type abutment bridge. A detailed numerical model of the representative bridges is created in OpenSees to perform dynamic analyses. To examine the effect of earthquake incidence angle on the fragility of skewed bridges, the representative bridge models are modified with different skew angles. Dynamic analyses for all bridge models are performed for all earthquake incidence angles examined. Simulated results are used to develop demand models and component and system fragility curves for the skewed bridges. The fragility characteristics are compared with regard to earthquake incidence angle. The results suggest that the earthquake incidence angle more significantly affects the seismic demand and fragilities of the integral abutment bridge than the skewed abutment bridge. Finally, a recommendation to account for the randomness due to the ground motion directionality in the fragility assessment is made in the absence of the predetermined earthquake incidence angle.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.781-790
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• 1999

In this paper we consider estimation of cancer incidence rates for local areas. The raw estimates usually are based on small sample sizes and hence are usually unreliable. A hierarchical Bayes generalized linear model is used which connects the local areas thereby enabling one to 'borrow strength' Random effects with pairwise difference priors model the spatial structure in the data. The methods are applied to cancer incidence estimation for census tracts in a certain region of the state of New York.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.1011-1014
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• 2014

Background: Soft tissue sarcomas (STS) represent 1% of all malignant lesions. In this study the authors analyzed the incidence of STS in Vojvodina (the north region of Serbia) in the period from 1985 to 2009. A number of studies conducted worldwide indicate that STS incidence rates are tending to increase. Materials and Methods: On the basis of data from the Cancer Registry of Vojvodina, age standardized STS incidence rates were established as well as their linear trend, with data on histological structure, age, gender and STS distribution at specific locations. Results: The total number of registered patients was 1,308. Average age standardized rate was 1.90/100,000 per year. The investigated period showed a slight increase in the incidence rate (average annual percent increase=0.77%). The most frequent histological type was sarcoma not otherwise specified-NOS (27%), followed by leiomyosarcoma (21%), liposarcoma (14%), rhabdomyosarcoma (11%) and malignant fibrous histiocytoma (9%). The male/female ratio was 0.73:1. Every fifth patient was younger than 39. Conclusions: Comparison among eight international STS epidemiology studies show that the incidence rate range is between 1.4/100,000-5.0/100,000, though our finding is closer to the lower limit. Furthermore, the incidence rate increase was lower than that characteristic for the half of the analyzed studies. A partial explanation for that should be looked for among changes in diagnostic criteria and STS classifications.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.3
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• pp.151-162
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• 2024

As the incidence direction of ground motion (or seismic wave) changes, the seismic response of the structure will also change according to that direction. In order to analyze the effect of the seismic response of the example bridge according to the direction of incidence of ground motion, the acceleration response spectra (S_a-T1) corresponding to the 1-second period obtained for various angles of incidence were obtained. Using S_a-T1, 40 sets of orthogonal pairs of horizontal component seismic waves corresponding to 5 types of percentiles were generated. Seismic vulnerability analysis of the bridge piers was performed by obtaining the seismic response of an example bridge according to the direction of incidence of ground motion. By analyzing the seismic vulnerability analysis of seismic waves corresponding to five types of percentiles, it was found that the median value of the seismic vulnerability curve differs by about 1.2 to 2.6 times depending on the incident direction of the seismic wave. In other words, depending on the incidence direction of seismic waves, the degree of damage to the bridge structure can vary by about 1.2 to 2.6 times.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.185-197
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• 1998

Engineering design involves the specification of many variables that define a product, how it is made, and how it behaves. Before some variables can be determined, other variables must first be known or assumed. This fact implies a precedence order of the variables, and of the tasks of determining these variable consequently. Moreover, design of complex systems may involve a large number of design activities. In this paper, the activity-activity incidence matrix is considered as a representation of design activity analysis which mainly focuses on the precedence constraint. In order to analyze the activity-activity incidence matrix, a heuristic algorithm is proposed, which transforms an activity-activity, parameter-formula, and parameter-parameter incidence matrix into a lower triangular form. The analysis of the structured matrices can not only significantly reduce the overall project complexity by reorganizing few critical tasks in practice, but also aims at obtaining shorter times considering the solution structure by exploring concurrency.