• Journal of Community Nutrition
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• 제7권2호
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• pp.93-99
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• 2005

This study investigated associations between exercise habit and bone mineral density (BMD) and bone mineral content (BMC) in postmenopausal women. The BMD and BMC of the spinal skeleton was measured by dual energy x-ray absorptiometry. Exercise and energy expenditure of physical activity were estimated by questionnaire. For exercise activities, subjects were asked to identify all exercises they have participated in. The subjects were further asked to estimate the number of years of participation, the number of weeks per year, the number of times per week, and the number of hours per time. Subjects were then categorized into exercise (more than 3 times/wk, more than 30min per session exercise (n = 47) and nonexercise group (n = 72). Results indicated that there were no significant differences in BMD and BMC when comparisons were made between subjects in exercise habit, a general exercise group and a nonexercise control group. However, when exercise subjects were divided into weight-bearing and nonweight-bearing groups, significant differences were found. These results suggest that weight-bearing exercise positively influences bone mineral density and bone mineral content in postmenopausal women. Sedentary women should be encouraged to adopt a weight-bearing exercise to maintain the health of their skeletons. Exercise interventions are practical and feasible for healthy women and should be encouraged at the earliest possible age. Our findings lend support to recommendations for physical activity and weight-bearing exercise as a means of osteoporosis prevention.

• 한국의류학회지
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• 제46권3호
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• pp.481-493
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• 2022

This study investigated process conditions for 3D printing through manufacturing thermoplastic polyurethane (TPU) samples under different infill conditions. Samples were prepared using a fused deposition modeling 3D printer and TPU filament. 12 infill patterns were set (2D: grid, lines, zigzag; 3D: triangles, cubic, cubic subdivision, octet, quarter cubic; 3DF: concentric, cross 3D, cross, honeycomb), with 3 infill densities (20%, 50%, 80%). Morphology, actual time/weight and compressive properties were analyzed. In morphology: it was found that, as infill density increased, the increase rate of the number of units rose for 2D and fell for 3DF. Printing time varied with the number of nozzle movements. In the 3DF case, the number of nozzle movements increased rapidly with infill density. Sample weight increased similarly. However, where the increase rate of the number of units was low, sample weight was also low. In compressive properties: compressive stress increased with infill density and stress was high for the patterns with layers of the same shape.

• Journal of Advanced Marine Engineering and Technology
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• 제38권8호
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• pp.981-994
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• 2014

Density currents formed by buoyancy discharges from rivers are numerically studied using non-dimensional two layer model including Coriolis acceleration, bottom stress, interfacial friction. Some typical numbers such as Froude number, densimetric Froude number and Kelvin number are obtained and some characteristic scales are defined as a result of non-dimensionalization of the governing equations. Besides the Coriolis effect, the configurations of bottom topography, bottom friction coefficient and interfacial friction are found to significantly affect the propagation of the warm water plume. Frontal position can fastly propagate in the case of large density difference between the two layers and small interfacial friction. Left side boundary current is easily formed under the small interfacial friction. With large Kelvin number, both right and left side boundary currents are formed. Wave-like disturbances and eddies are easily formed under the high Froude number.

• 한국조경학회지
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• 제18권2호
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• pp.15-19
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• 1990

도시공원의 혼잡에 관해 실제 이용자가 느끼는 혼잡정도와 이용밀도를 중심으로 조사한 결과 다 음과 같이 요약할 수 있다. 이용밀도는 계절과 요일에 따라 큰 차이가 있으며 외국에 비해 상당한 과밀이용을 나타내고 있었다. 이용밀도와 혼잡간에는 높은 상관성을 보이고 있으며 고밀도에서 이용자가 증가할 때 보다 저밀도에서 이용자가 추가될 때 혼잡도에 더 큰 영향을 미쳤다. 이용자가 증가 하여도 혼잡에는 크게 영향을 미치지 않는 혼잡포화점에서의 1인당 공원이용가능 면적이 약10$m^2$로서 우리민족의 밀집공간에 대한 강한 내성을 나타내었다. 앞으로는 본연구에서보다 다양하고 폭넓은 공원녹지를 대상으로 한 실증적 연구가 뒤따라야 할것으로 생각된다.

• 설비공학논문집
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• 제8권3호
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• pp.338-350
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• 1996

A numerical analysis is carried out to study the two-dimensional steady state natural convection from vertical wires immersed in cold pure water. The surface of the wire is $0^{\circ}C$ unifrom temperature. Results of the analysis are presented for free stream temperature from $0^{\circ}C$ to $25^{\circ}C$ and the aspect ratio N from $5.26{\times}10^{-3}$ to $1.0{\times}10^{-3}$. The effects of the density extremum and aspect ratio on the flow pattern and the heat transfer characteristics are discussed As the aspect ratio N becomes larger, in the range of $1.0^{\circ}C{\leq}T_{\infty}{\leq}4.4^{\circ}C$ and $6{^{\circ}C}{\leq}T_{\infty}{\leq}17^{\circ}C$, the effect of Pr number on the heat transfer is shown to be more significant than the aspect ratio. Investigating into the effect of the density extremum on the heat transfer from wires, the new heat transfer correlations are suggested with the relation of average Nu mumber vs. modified Ra number. Here, the coefficient values C of correlations are presented as the function of density extremum parameter $R^*$. The effects of the density extremum parameter are also discussed.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.147-153
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• 2023

In recent times, an absence of effective crowd management has led to numerous stampede incidents in crowded places. A crucial component for enhancing on-site crowd management effectiveness is the utilization of crowd counting technology. Current approaches to analyzing congested scenes have evolved beyond simple crowd counting, which outputs the number of people in the targeted image to a density map. This development aligns with the demands of real-life applications, as the same number of people can exhibit vastly different crowd distributions. Therefore, solely counting the number of crowds is no longer sufficient. CSRNet stands out as one representative method within this advanced category of approaches. In this paper, we propose a crowd counting network which is adaptive to the change in the density of people in the scene, addressing the performance degradation issue observed in the existing CSRNet(Congested Scene Recognition Network) when there are changes in density. To overcome the weakness of the CSRNet, we introduce a system that takes input from the image's information and adjusts the output of CSRNet based on the features extracted from the image. This aims to improve the algorithm's adaptability to changes in density, supplementing the shortcomings identified in the original CSRNet.

• 한국응급구조학회지
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• 제28권1호
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• pp.63-76
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• 2024

Purpose: To analyze trends related to demography and EMS and to provide supporting data for the appropriate deployment of EMS providers. Methods: In this cross-sectional study, data on patients transported by 119 EMS, demographics, and EMS factors were collected using the Korean Statistical Information Service (KOSIS) and the National Fire Agency annual report from 2017 to 2021. Results: During the study period, the total number of patients and those with severe disorders transported via 119 EMS showed an increasing trend. The total fertility rate and population during the same period tended to decrease, and the population density and number of households increased; however, there was a disparity between regions. The main demographic factors affecting the number of patients transported were population density and total fertility rate, while the main EMS factors were the number of ambulances and provision of emergency medical information services(hospital guidance, pharmacy information, and first aid guidance). Conclusion: From the perspective of EMS providers' force deployment, it is necessary to consider population density, population, number of households, total fertility rate, and number of emergency medical institutions and to strengthen the role of diverting the use of 119 EMS by minor patients by providing emergency medical information.

• Applied Microscopy
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• 제50권
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• pp.6.1-6.6
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• 2020

The cerebellum is a region of the brain that plays an important role in motor control. It is classified phylogenetically into archicerebellum, paleocerebellum and neocerebellum. The Purkinje cells are lined in a row called Purkinje cell layer and it has a unique dendritic branches with many spines. The previous study reported that there is a difference of synapse density according to the lobules based on large two-dimensional data. However, recent study with high voltage electron microscopy showed there was no differences in dendritic spine density of the Purkinje cell according to its phylogenetic lobule. We analyzed Purkinje cell density in the II, VI and X lobules by stereological modules and synaptic density was estimated by double disector based on Purkinje cell density in the molecular layer of each lobule. The results showed that there was significant difference in the Purkinje cell density and synapse number according to their phylogenetic lobules. The number of Purkinje cell in a given volume was larger in the archicerebellum, but synapse density was higher in the neocerebellum. These data suggest that cellular and synaptic organization of the Purkinje cell is different according to their phylogenetic background.

• The Korean Journal of Ecology
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• 제9권1호
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• pp.73-78
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• 1986

The effects of density and soil nutrient regime on competition between individuals in pure and mixed populations of two annuals. Chenopodium album and Digitaria sanguinalis were investigated at the level of enegy allocation. Seedling emergence of two species was extremely high (>90%) in both pure and mixed culture irrespective of the density and nutrient regime, but percentage of seedling establishment or fertile plant became gradually low with increasing density owing to 'self-thinning'. The mean plant dry weight was significantly reduced with increasing density and decreasing soil fertility. The dry matter production of D. sanguinalis in mixture was markedly greater than in pure culture under medium and high density. Also, as considered the number of seed production as reproductive allocation, relationship between them and the number of seed production per plant showed a similar tendency. Therefore, these results indicated that D. sanguinalis had a greater competitive advantage than C. album and energy allocations to variious organs were regulated by plastic response rather than determined genetically.

• 대한수학회논문집
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• 제20권4호
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• pp.813-826
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• 2005

Regarding all particles at a fixed site as a cluster, the size of the largest cluster under the zero range invariant measures is well studied by Jeon et al.[5] for the case of density one. Here, the density of the finite zero-range process is given by the ratio between the number m of particles and the number n of sites. In this paper, we study the lower density case, i.e., the case m = o(n). Especially, when m ~ $n^{\beta}$,0 < ${\beta}$ < 1, we show that there is an interesting cutoff point around $\beta$ = 1/2.