• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.385-393
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• 2009

This study grasped the relationship between relative humidity in concrete and concrete shrinkage followed by pre-absorbed water of porous lightweight aggregates through measurements of concrete shrinkage and humidity and comparisons with established research results. It was showed that shrinkage reduction effect of lightweight concrete is 36% at 7 days early ages and 25% at 180 days long-term ages when water-binder ratio is 0.3. It also showed that shrinkage reduction effect is 19% at 7 days and 16% at 180 days when water-binder ratio is 0.4 and 37%, 32% when water-binder ratio is 0.5. The moisture supply effect of lightweight aggregates was remarkable at early age within 7~10 days irrespective of water-binder ratio. In case of waterbinder ratio is 0.3, the relationship between shrinkage and internal humidity of concrete has been underestimated regardless of applied existing model type and in case of water-binder ratio is 0.4, 0.5, measurement values are relatively similar with existing model equations. Finally this study did regression analyses about the relation among the humidity change and the shrinkage strain as a high-degree polynomial and derived parameters that can connect moisture movement analysis with differential shrinkage analysis in case of considering relative humidity at the time by moisture movement analysis of concrete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.841-851
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• 2019

This study presents risk ranking by accident types at intersections, crosswalk and tunnel sections. An ordered logit model was used to estimate the accident severity of traffic accidents based on 58,868 accident records that have occurred on the Seoul and Gyeonggi-do over the period 2014-2017. The factors affecting the injury severity were identified by the estimated model first, and risk ranking was proposed according to conditions of accident occurrence using relative ratio analysis later. The analysis results showed that the injury severity dramatically depends on the location and time of the accident. The analysis results showed that the injury severity dramatically depends on the location and time of the accident. Furthermore, there are severe injury cases in terms of the injury severity despite the small number of occurrence of traffic accident, or there are severe injury cases in terms of the injury severity despite the high frequency of occurrence of traffic accident.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.149-157
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• 1994

To investigate the causes of distribution of Kummerowia striata (Thunb.) Schindl. mostly restricted on the roadside and reclaimed land, plant growth was analyzed under different of tread-pressures: $P_1$(10 times/day, $16.34Kg/cm^2$), $P_2$(20 times/day, $31.52 Kg/cm^2$), $P_3$(30 times/day, $40.79 kg/cm^2$) and the control $P_c$(0 times/day, $3.73 Kg/cm^2$). The matter production in the $P_1$decreased compared with that in the $P_c$, and those in the $P_2$and $P_3$ continuously decreased so that its length growth gradually decreased and, in particular, the growth of leaves and nodule was suppressed. The number of leaves and roots tended to increase in the $P_2$and $P_3$. The water contents of roots following the increase of tread-pressure increased continuously. Following the increase of tread-pressure, T/R ratio and C/F ratio tended to increase. Kummerowia striata showed the highest growth in the $P_c$ and showed 26% relative growth in the $P_1$compared with that in the $P_c$. This plant showed 8% relative growth in the $P_3$, which is excess to the tread-pressure $21Kg/cm^2$, the limit of growth in the plant. Because this plant grew continuously in the P$_3$, the tread-pressure is regarded as an important factor affecting the roadside distribution of this plant.

• Journal of Oriental Neuropsychiatry
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• v.14 no.1
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• pp.183-192
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• 2003

Objective : Obesity is related to psychological problems as well as physical problems. This study was designed to investigate the depression of over weight and normal group who visited to obesity clinic for diet therapy. Methods : 67 patients were selected(obesity group 42, normal group 25), they were treated medically in obesity clinic of Dong-Seo Oriental Hospital. We checked age, sex, education level, relative weight, BMI and Beck Depression Inventory(BDI) in two group. Results : The results were summarized as followed. 1. The ratio of Relative Weights are $137.45{\pm}12.77$ in over weight group, $108.48{\pm}9.11$ in normal group. 2. The ratio of BMI are $28.61{\pm}2.94$ in over weight group, $23.04{\pm}1.83$ in normal group. 3. The results of BDI score are $10.60{\pm}7.15$ in over weight group, $12.56{\pm}8.33$ in normal group. Conclusions : These results suggested that the patients who participated in diet therapy had mild depression and we should pay attention to psycological problem as well as the physical problem when we treat obesity.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.671-674
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• 2007

In this paper, the EM wave absorber was designed and fabricated for ETC system, because ETC system has some problems including signal error and system-to-system interference. We fabricated some samples in different composition ratio of MnZn-ferrite, Carbon and CPE, confirmed that optimum composition ratio of Mn2n-ferrite, Carbon, CPE was 40 : 15 : 45 wt%. Complex relative permittivity and complex relative permeability was calculated by the measured data. And absorption abilities were simulated according to different thickness of the EM wave absorbers using complex relative permittivity and permeability. The EM wave absorber was fabricated based on simulated data Simulated and measured values agree well. As a result, the developed EM wave absorber has a thickness of 3.38 mm and absorption ability over 20 dB at 5.8 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1906-1914
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• 2012

In this paper, relative service differentiation in JET based optical burst-switched networks with deflection routing is presented. It differs from conventional schemes in that it tries to make the loss rate of high class bursts as low as possible while maintaining the desired proportional ratio between the high class bursts and low class bursts. Strategies applied to it are dynamic wavelength allocation and the preemption which are combined to deflection routing. With dynamic wavelength allocation, the number of wavelengths allocated to high class bursts are dynamically changed. Preemption which gives more preference to high class bursts is also applied to decrease its loss rate. To lower the loss rate, deflection routing is applied for any kind of traffic. With those strategies, the suggested scheme shows desired properties that the loss rate of high class traffic is as lowered as possible. A queueing model for the scheme is developed to approximate loss ratio and the numerical results show that the proposed scheme provisions relative service differentiation.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.362-366
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• 2007

This study was conducted to evaluate the status of habitat distribution, environmental characteristics and plant species growing with Lonicera japonica in its habitats. In the distribution of plant coverage below 30%, it was 84.6% in the inland area and 80.7% in the seashore area. There was similar coverage in both inland and seashore areas. But the average relative coverage in the seashore area was 26.1%, which is a little higher than that of the inland area (22.5%). In the habitats, both inland and seashore areas showed a high distribution ratio below 10 degrees. But among them, inland areas showed a high distribution ratio (62.4%) below 10 degrees, which was about twice as much as the seashore areas (32.2%). Habitat distribution was most often found on the southern slopes in both inland and seashore areas. The average soil pH of Lonicera japonica habitat was 5.2 in the inland areas and 6.9 in the seashore areas. Also, the seashore areas showed little content of $P_2O_5$, but high content of K, Mg, Na on the other hand compared to the inland area. Miscanthus sinensis was the highest importance value (16.4) among plants growing with Lonicera japonica in their habitats in both inland and seashore areas. But in the inland areas, Artemisia princeps showed the highest importance value, and Miscanthus sinensis was the highest in the seashore areas.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.207-211
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• 2004

The final goal of this research is to establish the relative dangerousness D/B for factors on seakeeping performance. This D/B is essential to develope the seakeeping performance evaluation system built-on-ship. The system is composed of the apparatus for measuring a vertical acceleration to be generated by the ship's motions, computer for calculating the synthetic seakeeping performance index and monitor for displaying the evaluating diagram of navigational safety of ship. In this paper, a methodology on the establishment of the relative dangerousness D/B for factors on seakeeping performance is presented by a numerical simulations, playing an important role on the algorithm of the program for calculating the synthetic seakeeping performance index. Finally, It is investigated whether the relative dangerousness D/B can be realized an accurate values according to the loading conditions, weather conditions, wave directions end present ship's speed of a model ship.

• The KIPS Transactions:PartC
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• v.12C no.7 s.103
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• pp.1007-1014
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• 2005

A generation of rules or patterns for detecting attacks from network is very difficult. Detection rules and patterns are usually generated by Expert's experiences that consume many man-power, management expense, time and so on. This paper proposes statistical methods that effectively detect intrusion and attacks without expert's experiences. The methods are to select useful measures in measures of network connection(session) and to detect attacks. We extracted the network session data of normal and each attack, and selected useful measures for detecting attacks using relative entropy. And we made probability patterns, and detected attacks using likelihood ratio testing. The detecting method controled detection rate and false positive rate using threshold. We evaluated the performance of the proposed method using KDD CUP 99 Data set. This paper shows the results that are to compare the proposed method and detection rules of decision tree algorithm. So we can know that the proposed methods are useful for detecting Intrusion and attacks.

• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.