• Toxicological Research
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• v.20 no.1
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• pp.55-61
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• 2004

Respiratory effects in full time welders include bronchitis, airway irritation, lung function changes, and lung fibrosis. Welder's pneumoconiosis has been generally determined to be benign and not associated with respiratory symptoms based on the absence of pulmonary function abnormalities in welders with marked radiographic abnormalities. Accordingly, to investigate pulmonary function changes during 60 days induced by welding-fume exposure, male Sprague-Dawley rats were exposed to manual metal arc-stainless steel (MMA-SS) welding fumes with concentrations of 64.8$\pm$0.9 mg/$m^3$ (low dose) and 107.8 $\pm$ 2.6 mg/$m^3$ (high dose) total suspended particulates for 2 hr/day, 5 days/week in an inhalation chamber for 60 days. Pulmonary function was measured every week with whole body plethysmograph compensated (WBP Comp, SFT38116, Buxco Electronics, Sharon, CT). The rats exposed to the high dose of welding fumes exhibited statistically significant (p<0.05~0.01) body weight decrease as compared to the control whereas cell number increase of the bronchoalveolar lavage fluid (BALF) (total cell, macrophage, polymorphonuclear cell and lymphocyte) during the 60 days exposure period. And only tidal volume was significantly decreased in dosedependantly during 60 days of MMA-SS welding fume exposure. This pulmonary function change with inflammatory cell recruitment confirms the lung injury caused by the MMA-SS welding fume exposure.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.216-216
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• 2011

We will investigate the bonding configurations of phenylalanine and tyrosine adsorbed on the Ge(100) surface using CLPES and DFT calculations. First, the C 1s, N 1s, and O 1s spectra obtained at 300 K revealed that both the amine and carboxyl groups of phenylalanine and tyrosine concurrently participated in adsorption on the Ge(100) surface without bond breaking using CLPES, depending on the extent of coverage. In the second place, we confirmed that the "O-H dissociated-N dative bonded structure" is the most stable structure implying kinetically favorable structure, and the "O-H dissociation bonded structure" is another stable structure manifesting thermodynamically advantageous structure using DFT calculations. This tendency turns up both phenylalanine and tyrosine, similarly. Furthermore, through the CLPES data and DFT calculation data, we discovered that the "O-H dissociated-N dative bonded structure" and the "O-H dissociation bonded structure" are preferred at 0.30 ML and 0.60 ML, respectively. Moreover, we found that the phenyl ring of phenylalanine is located in axial position to Ge(100) surface, but the phenyl ring of tyrosine is located in parallel to Ge(100) surface using DFT calculations.

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.338-344
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• 2021

Solitary fibrous tumors (SFT) are rare mesenchymal tumors that most commonly develop in the pleura; they rarely involve the diaphragm. MRI has not been widely used to evaluate SFTs of the thoracic cavity, though it may be highly useful in assessing local invasion, predicting malignant potential, and helping in the differential diagnosis. However, MRI findings of malignant SFTs of the diaphragmatic pleura have been described in only two cases. We report a rare case of a malignant solitary fibrous tumor of the diaphragmatic pleura in an 82-year-old man. We describe the clinical and characteristic imaging features, including computed tomography, conventional MRI, and diffusion-weighted imaging. Contrast-enhanced MRI is more accurate than is CT in identifying the origin of SFTs, predicting whether they ae benign or malignant, and assessing local invasion. This imaging modality proved helpful in deciding on the treatment strategy for these rare tumors.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.393-396
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• 2008

센서 네트워크에서 병합 질의를 효율적으로 처리하기 위한 다양한 인-네트워크 질의 처리 기법이 제안되었다. 스카이라인 질의는 일반적인 병합 질의와 달리 다차원 데이터에 대한 비교를 요구하므로 인-네트워크 처리가 쉽지 않다. 스카이라인 질의를 에너지 효율적으로 처리하기 위해서 불필요한 데이터의 전송을 제거하는 것이 중요하다. 기존에 제안된 스카이라인 처리 기법은 전체 네트워크에 필터를 배포함으로써 불필요한 데이터 전송을 차단한다. 하지만 많은 False Positive 발생에 따른 불필요한 데이터 전송과 필터 배포시 발생하는 에너지 소모로 인해 네트워크의 수명이 단축된다. 본 논문에서는 필터 배포에 따른 에너지 소모를 줄이기 위한 방법으로 상향식 필터 설정을 통한 스카이라인 질의 처리 기법과 필터링 성능을 향상시키는 기법을 제안한다. 제안하는 기법은 데이터를 수집하는 과정에서 스카이라인 필터테이블(SFT)설정하는 상향식 필터링을 수행한다. 그리고 선-필터링(Pre-filtering) 기법을 통해 필터효과를 증가시킨다. 제안하는 알고리즘의 우수성을 보이기 위해 시뮬레이션을 통해 기존에 제안된 MFTAC기법과 비교하였으며, 그 결과 평균 False Positive가 평균 84.44% 감소하였고, 네트워크 수명이 약 75.99% 증가하였다.

• Structural Engineering and Mechanics
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• v.90 no.1
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• pp.41-49
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• 2024

In recent years, China's high-speed railway (HSR) line continues to expand into seismically active regions. Analyzing the features of earthquake rail irregularity is crucial in this situation. This study first established and experimentally validated a finite element (FE) model of bridge-track. The FE model was then combined with earthquake record database to generate the earthquake rail irregularity library. The sample library was used to construct a model of desired earthquake rail irregularity based on signal processing (SFT) and hypothesis principle. Finally, the effects of random pier height and random span number on desired irregularity were analyzed. Herein, an equivalent method of calculating earthquake rail irregularities for random structures was proposed. The results of this study show that the amplitude of desired irregularity is found to increase with increasing pier height. When calculating the desired irregularity of a structure with unequal pier heights, the structure can be regarded as that with equal pier heights (taking the largest pier height). For a structure with the span number large than 9, its desired irregularity can be considered equal to that of a 9-span structure. For the structures with both random pier heights and random span number, their desired irregularities are obtained by equivalent calculations for pier height and span number, respectively.

• Journal of Korean Biological Nursing Science
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• v.13 no.3
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• pp.276-282
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• 2011

Purpose: The aim of the present study was to investigate the effects of a aquatic exercise program on body mass index, body fat percentage and skeletal muscle mass, physical fitness using SFT (senior fitness test) and depression in elderly women. Methods: This study included 59 elderly women. Aquatics exercise program was performed three times per week for 12 weeks using rating of perceived exertion and body mass index, body fat percentage, skeletal muscle mass, physical fitness and depression were measured before and after exercise program. Statistical analysis was performed using t-test. Results: Body mass index (p=.002) and body fat percentage (p=.021) were significantly decreased after aquatic exercise program. Chair stand (p=.009), 2 minute step test (p<.001), back scratch (p<.001), and chair sit and reach (p<.001) were significantly increased after the aquatic exercise program. But, there was no significant differences in the depression. Conclusion: It is suggested the aquatic exercise program may play a significant role in improving body fat and physical fitness in the elderly women. However, as well as aquatic exercise program, sustained encouragement are required to improve physical and psychological traits.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.3
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• pp.63-72
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• 2023

Background: This study investigated the effects of face-to-face and non-face-to-face McKenzie exercises and elastic band strengthening exercises on falls and fitness in older adults. Methods: A total of 44 subjects were divided into a face-to-face group (FG; n=22) and a non-face-to-face group (NFG; n=22) who met older adults. Both groups used McKenzie exercises and strength training with elastic bands The fall efficacy scale (K-FES) and glycosylated hemoglobin (HbA1c) Pro were used to compare the senior fitness test (SFT). Results: No significant differences were detected between the two groups before the intervention; however, a significant difference was noted in the K-FES scores after the intervention. The change in HbA1c after the intervention was not statistically significant in the FG or the NFG, and no significant difference was detected between the two groups. The change in lower limb muscle strength in the elderly physical fitness test showed no significant difference between the two groups before or after the intervention. The change in upper limb flexibility after the intervention was not significantly different in the FG or NFG, indicating no significant difference between the two groups. The change in the 3-meter round-trip test after the intervention was significantly different in both the FG and NFG groups, but the difference between the groups was not statistically significant. The change in the grip strength test of the dominant hand showed no significant difference after the intervention in the FG or the NFG, and the difference between the FG and NFG groups was not statistically significant. The dominant foot external standing after the intervention was significantly improved in the FG, but no significant difference was detected in the NFG, and the difference between the two groups was not statistically significant. Conclusion: The study findings revealed that FG and NFG McKenzie exercises and elastic band strengthen exercises were equally effective at preventing falls and improving fitness in older adults.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.1
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• pp.77-89
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• 2020

Submerged floating tunnel (SFT) is a type of tunnel that allows tunnel segments to float underwater by buoyancy, and is being actively studied in recent years. When the submerged floating tunnel is connected to the ground, the tunnel and the bored tunnel inside the ground must be connected. There is risk that the stress will be concentrated at the connection between the two tunnels due to the different constraints and behavior of the two tunnels. Therefore, special design and construction methods should be applied to ensure the stability around the connection. However, previous studies on the stability at the connection site have not been sufficiently carried out, so study on the basic stage of the stability at connection site are necessary. In this study, numerical analysis simulating the connection between submerged floating tunnel and the bored tunnel confirmed that the shear strain concentration occurred in the ground around the connection, and it was analyzed that the structural factors can be handled during construction to have effects on the stability of the ground around the connection. Numerical results show that the risks from disproportionate displacements in the two tunnels can be mitigated through the construction of grouting material and joint design. Although the results from this study are qualitative results, it is expected that it will contribute to the determination of structural factors and risk areas that should be considered in the design of connections between the submerged floating tunnel and bored tunnel in the future studies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.955-967
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• 2016

As transportation systems for connecting lands and islands, oversea long-span bridges, underwater tunnels, and immersed tunnels have been mainly used so far. Submerged floating tunnels (SFTs) moored under specific water depth are one of the newest oversea transportation system. Compared to other existing systems, the new system requires relatively less construction cost and time. But, there is still no construction example. For reasonable design of the tunnel and mooring lines the rational structural analysis should be firstly performed. Unlike common transportation structures, the submerged tunnels are mainly affected by the wave, vary irregular excitation component. So, the analysis scheme might be difficult because of the characteristics of the submerged structures. This study aims to suggest the rational global performance analysis methodology for the submerged tunnels. Using ABAQUS the dynamic response of the experimental models studied by KIOST (2013) was investigated considering regular waves. By comparing the simulation results with the experimental results, the feasibility of the numerical simulation was verified. Using the suggested method, the effects of initial inclination of the tethers and draft of the tunnel on the dynamic behavior were studied. In addition, dynamic response of a SFT under the irregular wave was examined.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.7-14
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• 2004

This study was conducted to investigate the effect on agricultural environment and crop productivity by different amount of applied fertilizer in consideration of irrigation water quality. N, P and K contents of irrigation water used in this experiment were 6.16, 0.26 and 9.37 mg/L, respectively. N, P and K Concentrations of runoff water were lower than those of inflow water during rice cultivation. N, P and K Concentrations of ponded and percolated water were changed according to the amount and time of applied fertilization. During rice cultivation in paddy soil, nitrogen balance was closed to 0 in SFT 50% (50% level of soil testing fertilization), 0.14 kg/ha, but it was 95.3 kg/ha in CF (conventional fertilization) treatment In SW 50% and STF (soil testing fertilization) treatment yield of perfect rice was not greatly different as compared with CF treatment due to the superiority of ripening rate, 1,000 grains weight and milling characteristics. Mechanical paratability of rice was excellent in NF (non fertilization) treatment, STF 50% treatment showed higher in nutrient availability and fertilizers use efficiency than other treatments.