• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.4
• /
• pp.106-113
• /
• 2002

In spacecraft system, structure subsystem has the mission of supporting all the components safely under various space environmental conditions. The safety of spacecraft structure is finally verified from the coupled load analysis, which is a branch of load analysis which combines the launch vehicle and satellite. This study introduces the optimization algorithm to reduce the weight of spacecraft structure under launch environmental conditions directly. The acceleration responses are obtained by the introduction of coupled load analysis, which lead to check the failure of spacecraft structural members. The results show a 12% saving of structural weight and this saving is mainly driven by the thickness of honeycomb core, which strongly affects the natural frequencies of platforms and panels.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.7
• /
• pp.1163-1169
• /
• 2015

Poly-gamma-glutamic acid (γ-PGA) is a natural polymer that is synthesized by Bacillus species and has been reported to have antitumor activity. The aim of this study was to investigate the effect of γ-PGA on the treatment of vaginal intraepithelial neoplasia (VAIN). A retrospective observational study on γ-PGA therapy for biopsy-proven VAIN was conducted. The efficacy was assessed by evaluating the results of Pap cytology and the viral load of high-risk HPV at three time points: at enrollment, and at the first and second post-treatment visits. Of 17 patients treated with γ-PGA, only 12 patients who had a high-risk HPV infection were included in the analysis. Histology was VAIN1 in seven patients, VAIN2 in two patients, and VAIN3 in three patients. γ-PGA was administered for newly diagnosed VAIN in five (41.7%) patients and persistent VAIN in seven (58.3%) patients for the mean time of 4.5 months. At the first and second post-treatment visits, cytological regression was observed in five (41.7%) and six (50%) patients, respectively. Regarding the HPV load, the overall response rate was 66.7%, and the mean level was 670.6 ± 292.5 RLU at the first follow-up, which was lower than the initial viral load of 1,494.8 ± 434.5 RLU (p = 0.084). At the second follow-up, the overall response rate was 58.3%, and the mean viral load level was 924.2 ± 493.7 RLU. γ-PGA may be helpful for the cytological regression and reduction of viral load in patients with high-risk HPV-positive VAIN, suggesting that γ-PGA is a promising treatment option for primary or persistent VAIN.

• Geomechanics and Engineering
• /
• v.10 no.3
• /
• pp.335-355
• /
• 2016

Most laboratory test research has focused on grouting efficiency in homogeneous reconstituted soft clay. However, the natural sedimentary soils generally behave differently from reconstituted soils due to the effect of soil structure. A series of laboratory grouting tests were conducted to research the effect of soil structure on the performance of compensation grouting. The effects of grouting volume, overlying load and grouting location on the performance of compensation grouting under different soil structures were also studied. Reconstituted soil was altered with added cement to simulate artificial structured soil. The results showed that the final grouting efficiency was positive and significantly increased with the increase of stress ratio within a certain range when grouting in normally consolidated structured clay. However, in the same low yield stress situation, the artificial structured soil had a lower final grouting efficiency than the overconsolidated reconstituted soil. The larger of normalized grouting volume could increase the final grouting efficiency for both reconstituted and artificial structured soils. Whereas, the effect of the overlying load on final grouting efficiencies was unfavourable, and was independent of the stress ratio. As for the layered soil specimens, grouting in the artificial structured soil layer was the most efficient. In addition, the peak grouting pressure was affected by the stress ratio and the overlying load, and it could be predicted with an empirical equation when the overlying load was less than the yield stress. The end time of primary consolidation and the proportion of secondary consolidation settlement varied with the different soil structures, grouting volumes, overlying loads and grouting locations.

• Water Engineering Research
• /
• v.7 no.1
• /
• pp.1-8
• /
• 2006

Recently, the population growth and agricultural development are rapidly undergoing in the South-West Texas. The junction of three river basins such as Lavaca river basin, Colorado-Lavaca Coastal basin and Lavaca-Guadalupe Coastal basin, are interesting for non-point and point source pollutant modeling: Especially, the 2 basins are an intensively agricultural region (Colorado-Lavaca Coastal/Lavaca-Guadalupe Coastal basins) and several cities are rapidly extended. In case of the Lavaca river basin, there are many range land. Several habitat types wide-spread over three relatively larger basins and five wastewater discharge regions are located in there. There are different hazardous substances which have been released. Total nutrient loads are composed of land surface load and river load as Non-point source and discharge from wastewater facilities as point source. In 3 basins region, where point and non-point sources of poll Jtion may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to how to assess and control the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern as non-point source with water quality related to pesticides, fertilizer, and nutrients and as point source with wasterwater discharge from cities. The GIS technique has been developed to aid in the point and non-point source analysis of impacts to natural resource within watershed. This project shows the losses in $kg/km^2/year$ of BOD (Biological Oxygen Demand), TN (Total Nitrogen) and TP (Total Phosphorus) in the runoff from the surface of 3 basins. In the next paper, sediment contamination will show how to evaluate in Estuarine habitats of these downstream.

• The Journal of Korean Academy of Prosthodontics
• /
• v.34 no.3
• /
• pp.501-532
• /
• 1996

This study investigated the effects of cantilever length, location and load condition on stress distribution developed in the implants, prostheses and supporting tissues. The osseointegrated prostheses with two 10mm Branemark implants at 2nd premolar and 1st molar sites with cantilever extensions at 1st premolar, 2nd and 3rd molar sites were constructed. Under 100N, 200N of vertical and $45^{\circ}$ oblique loads at the cantilever pontics, stress distribution patterns and displacement were analyzed with three dimensional finite element method. The results were as follows : 1. The stress was concentrated at the joint of the cantilever pontic and implant superstructure, the neck of implant and the ridge crest near the cantilever But there was little load transfer to the lower supporting tissues of implants. 2. The implant near the cantilever was displaced inferiorly while the implant far from the cantilever was displaced superiorly. In horizontal direction the implants were displaced to the direction where the loads were applied, except the apexes of the implants. 3. In case of anterior cantilever, the stress and displacement were higher than the prosthesis connected with natural tooth. 4. The stress developed in the posterior cantilevered type was higher than in the anterior cantilevered type. The greastest stress was concentrated at the ridge crest near the posterior cantilever. 5. The longer the cantilever, the more the stress was developed and was concentrated at the joint of the cantilever pontic and implant superstructure. 6. Under oblique load, the stress was concentrated at the necks of implants and the ridge crests, but decreased at the joint of the cantilever pontic and implant superstructure than under vertical load.

• Horticultural Science & Technology
• /
• v.34 no.3
• /
• pp.495-509
• /
• 2016

Irrigation applications (IA) and increased bud load (BL) are fundamental practices that are used to achieve optimum yields in grape production, while maintaining fruit quality parameters. Two different irrigation amounts (IA-I and IA-II) based on growth stages, in addition to a non-irrigated (rain-fed) control, along with two different BL applications [normal bud load based on traditional pruning practices (1BL) and double bud load (2BL)] were evaluated over a two-year experiment for their effects on the biochemical composition of the berries. Berries from the rain-fed vines had higher sugar levels, whereas no significant change was detected in organic acid levels. The increased bud load (2BL) treatment yielded less sugar in the berries compared to the 1BL control in both years. The total non-colored phenolic compounds (NPC) were greater in the irrigated (especially IA-I) and 2BL treatments than in those of the rain-fed and 1BL control. However, total anthocyanin was greater in the non-irrigated and 1BL control than in the irrigated and 2BL treatments. The antioxidant contents of the berries also varied according to the treatments and years. Our results implied that implementing a higher bud load along with the IA-I irrigation application, in which irrigation applications were 50 and 75% of the cumulative evaporation from the Class A pan during berry set to veraison and veraison to harvest growth stages, respectively, can help in obtaining greater yields in high-plateau viticulture. Thus, if more buds are left on the vines, along with sufficient irrigation and rainfall, yield may increase while maintaining or increasing the biochemical composition of the berries.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.4
• /
• pp.37-44
• /
• 2019

The purpose of this study is to rationally determine the priority of seismic reinforcement of main(key) members of bridges. Cable Supported bridge was selected as the evaluation target and the reliability based on the probability distribution was used to evaluate the seismic fragility of the key members as a quantitative indicator. The safety factor, which is a random variable, is considered an artificial (fixed load and live load) load and a natural (earthquake, wind, temperature, etc.) load. The seismic load is applied as a possible earthquake during the lifetime of the bridge. From analyzing the fragility of each key member based on the seismic reliability, it can be concluded that the shoe (23.8%) was the most fragile, where the other members are ranked as place concrete (20.5%), pier (18.9%), foundation (17.3%) and cable (5.0%) respectively.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.960-964
• /
• 2011

High speed railway structure, contact of vehicle needs to design considering the running stability(dynamic behavior). Also, upper structure has to satisfy design standard about moving load, high speed train(KTX). So, the high speed railway structure has to satisfy the requirement of natural frequency, vertical acceleration on deck, face distortion and vertical displacement considering ride comfort, which is suggested Ho-nam high speed railway design standard. In this study, it was investigated and evaluated to the dynamic behavior for tow plate Girder railway bridge subjected to moving load considering real high speed train loads.

• Steel and Composite Structures
• /
• v.19 no.1
• /
• pp.1-19
• /
• 2015

The buckling analysis is presented for non-homogeneous (NH) orthotropic truncated conical shells subjected to combined loading of axial compression and external pressure. The governing equations have been obtained for the non-homogeneous orthotropic truncated conical shell, the material properties of which vary continuously in the thickness direction. By applying Superposition and Galerkin methods to the governing equations, the expressions for critical loads (axial, lateral, hydrostatic and combined) of non-homogeneous orthotropic truncated conical shells with simply supported boundary conditions are obtained. The results are verified by comparing the obtained values with those in the existing literature. Finally, the effects of non-homogeneity, material orthotropy, cone semi-vertex angle and other geometrical parameters on the values of the critical combined load have been studied.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.795-802
• /
• 2001

The commutation and control in matrix converters is more complicated as in voltage source converters. Natural freewheeling paths do not exist and the theoretic absent storage elements result in a direct coupled system of load and line currents as well as voltages. The paper offers an overview about staggered commutation and control policies in matrix converters. Based on the knowledge about load current direction and the signs of the line to line input voltages different multi-step commutation policies were derived. This paper examines the application of that policies in the case of space vector modulation and direct control methods with the focus on the resulting effects to the reference output voltage deviation.