• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.247-253
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• 2011

In 2009, the Korean international construction industry showed a great performance, totaling 49.1 billion of contract and then this achievement has been considered a key milestone presenting that the international construction industry is one of the primary export industries of Korea. However, because of the construction firms' equalized levels of technology and price competitiveness, the competition among bidders is becoming more intensive. Moreover, this changing market circumstance leads construction firms to apply for bidding with the lowest price that could not meet the expected profitability of a project. Therefore, to develop various strategies based on project characteristics becomes one of the critical capabilities that construction firms should possess. Based on these motives, this study is aimed to investigate associations among number of bidders, contract award rate, profitability on international projects. For the correlation analysis, a set of data is structured by collecting all projects ranging from 1993 to 2009, excluding projects funded by official development and domestic funds. The number of bidders were grouped depending on project characteristics such as market regions, project types, bidding types, and order organization types. As the result of correlation analysis, contract award rate increases as the number of bidders increase, but the relationship between the number of bidders and profitability is negative. Understanding the correlations among variables can be employed in developing strategies to improve construction firms' competitiveness in the international construction market.

• Smart Structures and Systems
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• v.20 no.5
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• pp.549-562
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• 2017

The US railroad network carries 40% of the nation's total freight. Railroad bridges are the most critical part of the network infrastructure and, therefore, must be properly maintained for the operational safety. Railroad managers inspect bridges by measuring displacements under train crossing events to assess their structural condition and prioritize bridge management and safety decisions accordingly. The displacement of a railroad bridge under train crossings is one parameter of interest to railroad bridge owners, as it quantifies a bridge's ability to perform safely and addresses its serviceability. Railroad bridges with poor track conditions will have amplified displacements under heavy loads due to impacts between the wheels and rail joints. Under these circumstances, vehicle-track-bridge interactions could cause excessive bridge displacements, and hence, unsafe train crossings. If displacements during train crossings could be measured objectively, owners could repair or replace less safe bridges first. However, data on bridge displacements is difficult to collect in the field as a fixed point of reference is required for measurement. Accelerations can be used to estimate dynamic displacements, but to date, the pseudo-static displacements cannot be measured using reference-free sensors. This study proposes a method to estimate total transverse displacements of a railroad bridge under live train loads using acceleration and tilt data at the top of the exterior pile bent of a standard timber trestle, where train derailment due to excessive lateral movement is the main concern. Researchers used real bridge transverse displacement data under train traffic from varying bridge serviceability levels. This study explores the design of a new bridge deck-pier experimental model that simulates the vibrations of railroad bridges under traffic using a shake table for the input of train crossing data collected from the field into a laboratory model of a standard timber railroad pile bent. Reference-free sensors measured both the inclination angle and accelerations of the pile cap. Various readings are used to estimate the total displacements of the bridge using data filtering. The estimated displacements are then compared to the true responses of the model measured with displacement sensors. An average peak error of 10% and a root mean square error average of 5% resulted, concluding that this method can cost-effectively measure the total displacement of railroad bridges without a fixed reference.

• Progress in Medical Physics
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• v.13 no.1
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• pp.32-36
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• 2002

For Intensity Modulated Radiation Therapy(IMRT), the spatial resolution of intensity map(IM) is limited by the width of multi-leaf collimator, which would make an effect on the conformity of the target, as well as organs at risk. Several Methods are suggested to increase the spatial resolution, which can be categorized by the hardware-dependent technique and the software-based technique. However the best solution might be to make the width of MLC finer. it has several obstacles in the respects of technical difficulty and cost. This preliminary study is designed to investigate the clinical effectiveness of the virtual-micro IMRT(VMIMRT) technique, one of the software-based technique. A particular intensity map was created, which has 42$\times$54 pixel dimension ,0.5cm pixel size and 15 intensity levels. Using this intensity map, segment fields of IMRT were generated with 1$\times$lcm, 0.5$\times$1cm, 0.5$\times$0.5cm(VMIM) beamlet size, respectively As results, we found that there was no evidence of improvement for VMIMRT, compared with the 0.5$\times$lcm beamlet size which can be delivered by 1cm width MLC. The reason seems to be due to the constraint of VMIMRT. Further study is required to prove the benefit of the VIMRT in clinical case like head and neck cancer, where is expected that higher resolution than 1cm is necessary.

• Journal of Convergence Society for SMB
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• v.3 no.2
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• pp.27-32
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• 2013

Wireless Body Area Networks (WBAN) have been made possible by the emergence of small and lightweight wireless systems such as Bluetooth, enabled devices and PDAs. Antennas are an essential part of any WBAN system and due to various technical requirements and physical constraints, careful consideration of their design and deployment is needed. This paper is proposing on the design of wearable antenna as parts of clothing to serve communications functions, such as tracking and navigation in health care applications. The substrates of the wearable antennas will be made from textile materials and since it is wearable, it should have a small size, be light weight, low maintenance, and unobtrusive. This proposed paper will also investigate the influence of different parameters for wearable antenna including types of textile/substrate to ensure that the antenna design satisfies WBAN requirements. The characteristics and behavior of the antenna need to adhere to specifications set by wireless standards and system technology requirements. This means that the transmitting and receiving frequency bands of the various units need to be chosen accordingly. Since there are restrictions on the level of power to which the human body can be exposed to, the antenna as well as other RF system components must be designed to meet these restrictions. Antenna gain, which directly affects power transmitted, is a critical parameter in ensuring power levels fall within the safety guidelines and so will be of primary importance in the design. The electromagnetic interaction between WBAN antennas and devices and the human body will also be explored.

• International Journal of Railway
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• v.2 no.3
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• pp.124-126
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• 2009

Energy savings can be achieved with optimum energy consumptions, brake energy regeneration, efficient energy storage (onboard, line side), and primarily with light weight vehicles. Over the last few years, the rolling stock industry has experienced a marked increase in eco-awareness and needs for lower life cycle energy consumption costs. For rolling stock vehicle designers and engineers, weight has always been a critical design parameter. It is often specified directly or indirectly as contractual requirements. These requirements are usually expressed in terms of specified axle load limits, braking deceleration levels and/or demands for optimum energy consumptions. The contractual requirements for lower weights are becoming increasingly more stringent. Light weight vehicles with optimized strength to weight ratios are achievable through proven design processes. The primary driving processes consist of: $\bullet$ material selection to best contribute to the intended functionality and performance $\bullet$ design and design optimization to secure the intended functionality and performance $\bullet$ weight control processes to deliver the intended functionality and performance Aluminium has become the material of choice for modern light weight bodyshells. Steel sub-structures and in particular high strength steels are also used where high strength - high elongation characteristics out way the use of aluminium. With the improved characteristics and responses of composites against tire and smoke, small and large composite materials made components are also found in greater quantities in today's railway vehicles. Full scale hybrid composite rolling stock vehicles are being developed and tested. While an "overdesigned" bodyshell may be deemed as acceptable from a structural point of view, it can, in reality, be a weight saving missed opportunity. The conventional pass/fail structural criteria and existing passenger payload definitions promote conservative designs but they do not necessarily imply optimum lightweight designs. The weight to strength design optimization should be a fundamental design driving factor rather than a feeble post design activity. It should be more than a belated attempt to mitigate against contractual weight penalties. The weight control process must be rigorous, responsible, with achievable goals and above all must be integral to the design process. It should not be a mere tabulation of weights for the sole-purpose of predicting the axle loads and wheel balances compliance. The present paper explores and discusses the topics quoted above with a view to strengthen the recommendations and needs for the weight optimization by design approach as a pro-active design activity for the rolling stock industry at large.

• Journal of Life Science
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• v.24 no.6
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• pp.700-706
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• 2014

Doxorubicin (trade name adriamycin), an anthracycline antibiotic, is commonly used in the treatment of a wide range of cancers, including hematological malignancies, many types of carcinoma, and soft tissue sarcomas. It is closely related to the natural product daunomycin, and like all anthracyclines, it works by intercalating DNA. Its most serious adverse effect is life-threatening heart damage. Its anti-metastatic mechanisms in human prostate carcinomas are not fully understood. In this study, we used LNCap human prostate carcinoma cells to investigate the inhibitory effects of doxorubicin on cell motility and invasion, two critical cellular processes that are often deregulated during metastasis. Doxorubicin treatment inhibited cell migration and invasiveness of LNCap cells without showing any toxicity. Doxorubicin treatment also suppressed the activity and expression of matrix metalloproteinase (MMP)-2 and MMP-9, which were associated with up-regulated expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in LNCap cells. Doxorubicin treatment also attenuated the expression levels of claudin family members (claudin-1, -2,-3 and -4), major components of tightening of tight junctions (TJs) and increased the tightening of TJs, as demonstrated by an increase in transepithelial electrical resistance. The present findings demonstrate that doxorubicin reduces the migration and invasion of prostate carcinomas LNCap cells by modulating the activity of TJs and MMPs.

• Journal of Preventive Medicine and Public Health
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• v.45 no.6
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• pp.394-401
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• 2012

Objectives: Diabetes and obesity each increases mortality, but recent papers have shown that lean Asian persons were at greater risk for mortality than were obese persons. The objective of this study is to determine whether an interaction exists between body mass index (BMI) and diabetes, which can modify the risk of death by cardiovascular disease (CVD). Methods: Subjects who were over 20 years of age, and who had information regarding BMI, past history of diabetes, and fasting blood glucose levels (n=16 048), were selected from the Korea Multi-center Cancer Cohort study participants. By 2008, a total of 1290 participants had died; 251 and 155 had died of CVD and stroke, respectively. The hazard for deaths was calculated with hazard ratio (HR) and 95% confidence interval (95% CI) by Cox proportional hazard model. Results: Compared with the normal population, patients with diabetes were at higher risk for CVD and stroke deaths (HR, 1.84; 95% CI, 1.33 to 2.56; HR, 1.82; 95% CI, 1.20 to 2.76; respectively). Relative to subjects with no diabetes and normal BMI (21 to 22.9 $kg/m^2$), lean subjects with diabetes (BMI <21 $kg/m^2$) had a greater risk for CVD and stroke deaths (HR, 2.83; 95% CI, 1.57 to 5.09; HR, 3.27; 95% CI, 1.58 to 6.76; respectively), while obese subjects with diabetes (BMI ${\geq}25kg/m^2$) had no increased death risk (p-interaction <0.05). This pattern was consistent in sub-populations with no incidence of hypertension. Conclusions: This study suggests that diabetes in lean people is more critical to CVD deaths than it is in obese people.

• KSBB Journal
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• v.15 no.5
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• pp.482-488
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• 2000

The Fab fraction of PDC-E2 specific human monoclonal antibody was produced using recombinant E. coli, and the effects of glucose and acetate were investigated to develop an optimal strategy for recombinant human antibody production. Higher glucose concentration in the culture media resulted inn higher cell growth and glucose consumption rate, which in turn resulted in an increased acetate production rate. When glucose was depleted, cells began to consume acetate as an energy source, and this consumption rate depended on the glucose concentration. When the residual glucose concentration was high, the accumulation of acetate was accelerated due to an increase in the acetate production rate and a decrease in the acetate consumption rate. Futhermore, it was found that a high accumulation of acetate, accompanied by a high glucose concentration, inhibited human antibody formation; the critical acetate concentration was $0.6g/\ell$. During production, a high glucose concentration enhanced cell growth, but inhibited antibody formation due to catabolic repression. Therefore, it is important to keep the concentration of both glucose and acetate as low as possible to increase antibody production after induction. Accordingly, it is important to accurately control the concentration of glucose and acetate in the culture media to obtain high cell densities and high productivity levels of recombinant human antibody.

• Journal of Intelligence and Information Systems
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• v.15 no.2
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• pp.15-31
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• 2009

The next generation IT environment is expected to be an open computing environment based on Grid computing technologies, which allow users to access to any type of computing resources through networks. The open computing environment has benefits in aspects of resource utilization, collaboration, flexibility and cost reduction. Due to the variation in performance of open computing resources, however, resource allocation simply based on users' budget and time constraints often fails to meet the Service Level Agreement(SLA). This paper proposes the Mean-Absolute Deviation(MAD) portfolio optimization approach, in which service brokers consider the uncertainty of performance of resources, and compose resource portfolios that minimize the uncertainty. In order to investigate the effect of this approach, we simulate an open computing environment with varying uncertainty levels, users' constraints, and brokers' optimization strategies. The simulation result concludes threefolds. First, the MAD portfolio optimization improves the success ratio of delivering the required performance to users. Second, the success ratio depends on the accuracy in predicting the variability of performance. Thirdly, the measured variability can also help service brokers expand their service to cost-critical users by discounting the access cost of open computing resources.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.209-220
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• 2017

The estrogen-mediated effect of mesenchymal stem cells (MSCs) is a highly critical factor for the clinical application of MSCs. However, the present study is conducted on MSCs derived from adult donors, which have different physiological status with steroid hormonal changes. Therefore, we explores the important role of $17{\beta}$-estradiol (E2) in MSCs derived from female and male newborn piglets (NF- and NM-pBMSCs), which are non-sexually matured donors with steroid hormones. The results revealed that in vitro treatment of MSCs with E2 improved cell proliferation, but the rates varied according to the gender of the newborn donors. Following in vitro treatment of newborn MSCs with E2, mRNA levels of Oct3/4 and Sox2 increased in both genders of MSCs and they may be correlated with both estrogen receptor ${\alpha}$ ($ER{\alpha}$) and $ER{\beta}$ in NF-pBMSCs, but NM-pBMSCs were only correlated with $ER{\alpha}$. Moreover, E2-treated NF-pBMSCs decreased in ${\beta}$-galactosidase activity but no influence on NM-pBMSCs. In E2-mediated differentiation capacity, E2 induced an increase in the osteogenic and chondrogenic abilities of both pBMSCs, but adipogenic ability may increased only in NF-pBMSCs. These results demonstrate that E2 could affect both genders of newborn donor-derived MSCs, but the regulatory role of E2 varies depending on gender-dependent characteristics even though the original newborn donors had not been affected by functional steroid hormones.