Since high-speed railway bridges are subjected to cyclic
loading by the continuous wheel loads traveling at high speed and regular
spacing, their dynamic behavior is of extreme importance and has significant
influence on the riding safety of the trains. To secure the
riding safety of the trains, advanced railway countries have limited the
vertical acceleration of the bridge slab below critical values at specific
frequency domains. Since these limitations of the vertical acceleration
constitute the most important factors in securing the dynamic safety of the
bridges, these countries have opted for a conservative approach. However, the
Korean specifications limit only the size of the peak acceleration without
considering the frequency domain, which impede significantly rational
evaluation of the high-speed railway bridges in Korea. In addition, the
evaluation of the acceleration without consideration of the frequency domain is
the cause of disagreement between the dynamic analysis and measurement results.
This study conducts field monitoring and dynamic analysis on high-speed railway
bridges to gather the acceleration signals and compare them. Significant
difference in the size of the vertical acceleration was observed between the
measured and dynamic analysis accelerations when discarding the frequency
domain as done in the current specifications. The comparison of the
accelerations considering only low frequencies below 30 Hz showed that the
dynamic analysis reflected accurately the measured vertical acceleration.

The design live load of
railway is divided into common railway and high-speed railway separately inKorea.
Accordingly, the Korean design specification of railway specifies the impact
factor for common railway and high-speed railway respectively. The impact
factor for high-speed railway is based on Eurocode. Since the impact factor
criteria inKoreawere established by adopting those of the Eurocode and without dedicated
investigation relying on research results reflecting the domestic
circumstances, thorough examination should be implemented on these criteria.
Therefore the evaluation of impact factor based on field tests is required.
Both dynamic and static vertical displacements are necessary to compute the
impact factor. The dynamic response can be obtained from the measurement of
deflection of the bridge slab crossed by the firstKoreahigh-speed train (KTX, Korea
Train eXpress) running at high-speed. The main difficulties encountered are in
obtaining static response because static response corresponds to the response
of the bridge when the train remains immobile on the bridge or crosses the
bridge at speed slower than5 km/hr. This study
introduces the static response derived by applying the moving average method on
the dynamic response signal. To that goal, field measurements was conducted
under train speeds of5 km/hr and ranging
from100 km/hr to300 km/hr
on Yeonjae Bridge located in the trial section of the Gyeonbu High-Speed
Railway Line before its opening. The validity of the application of the moving
average method is verified from comparison of measured static response and
derived static response by moving average method. Moreover, evaluation is
conducted on the impact factor computed for a bridge crossed by the KTX train
running at operational speed.

Abstract:
The objective of this study is to systematically assess the influences of the larynopharyneal anatomical details on airflow and particle behaviors during exhalation by means of image-based modeling. A physiologically realistic nose-throat airway was developed with medical images. Individual airway anatomy such as uvula, pharynx, and larynx were then isolated for examination by progressively simplifying this image-based model geometry. Low Reynolds number (LRN) k-w model and Langrangian tracking model were used to simulate the dynamics of airflow and particle transport for a wide range of exhalation conditions (4-45 L/min) and particle sizes (1 nm-1 μm). Results showed that pharyngeal anatomical details exerted a significant impact on breathing resistance and particle profiles. Abrupt pressure drop resulting from the uvula-related airway obstruction was observed. Even though the total deposition rate in the nasal airway is largely unaffected by the upstream effect, the local deposition patterns vary notably. Results of this study also indicate that the pressure drop appears to be an appropriate parameter to characterize the geometric variations for diffusive depositions. Inclusion of pressure drop (D^{0.5}Q^{-}^{0.62}dp^{0.07}) gives an improved correlation than using the conventional diffusion factor (D^{0.5}Q^{﹣}^{0.28}).

Abstract:
Upon treatment of 25(R)-spirost-5-en-3β-ol (diosgenin), 25(R)-1,4,6-spirostatrien-3-one and 25(R)-4,6-spirostadien-3β-ol with 30% H2O2 and 5% NaOH in methanol, diosgenin did not react, 25(R)-1,4,6-spirostatrien-3-one was converted to 25(R)-1α,2α-epoxy-4,6-spirostadien-3-one and 25(R)-4,6-spirostadien-3β-ol was oxidized to give a small amount of 25(R)-4,6-spirostadien-3-one, while most of the original starting material remained unchanged. On the other hand, reactions of diosgenin, 25(R)-1,4,6-spirostatrien-3-one and 25(R)-4,6-spirostadien-3β-ol with m-chloroperoxybenzoic acid in chloroform yielded 25(R)-5α,6α-epoxyspirostan-3β-ol, 25(R)-6α,7α-epoxy-1,4-spirostadien-3-one and 25(R)-4β,5β-epoxy-6-spirosten-3β-ol, respectively.

Abstract:
We consider open strings ending on a D5-brane in the pp-wave background, which is realized in the Penrose limit of $AdS_5 \times S^5$ with an $AdS_4\times S^2$ brane. A complete list of gauge invariant operators in the defect conformal field theory is constructed which is dual to the open string states.

Abstract:
As a preliminary study for the erection of floating structures using high performance concrete, this paper examines the bond characteristics between concrete and the reinforcing bar. Since the floating structure is constructed in aquatic environment, corrosion of the reinforcing steel is likely to develop more prematurely than in onshore structure in case of concrete cracking. A solution to this corrosion problem could use FRP rebar instead of steel reinforcement. To that goal, an experimental study is conducted on the concrete-FRP bond strength to verify if such FRP rebar develops performance comparable to the conventional steel rebar. A series of tests are performed considering the bond length of ordinary steel rebar and G-FRP rebar as test variable with respect to the strength of concrete, and the results are presented.

The research on positioning system and
spatial alignment is a big topic. In this paper, we proposed a design (that) studies
two issues. One is the study of range positioning algorithm based on ZigBee communication
system. The other one is spatial alignment platform
which is controlled with two servos. Hardware and software control system was
realized, which also consists of two parts, ZigBee network positioning system
and automatic orientation platform.

Abstract:
We use the supergravity modes to clarify the role of the prefactor in the light-cone superstring field theory on PP-wave background. We verify some of the proposals of the recent paper hep-th/0205089 and give further evidence for the correspondence between N=4 SYM gauge theory and string theory on PP-wave. We also consider energy-preserving processes and find that they give vanishing cubic interaction Hamiltonian matrix.

Abstract:
We study string interactions among string states with arbitrary impurities in the Type IIB plane wave background using string field theory. We reproduce all string amplitudes from gauge theory by computing matrix elements of the dilatation operator in a previously proposed basis of states. A direct correspondence is found between the string field theory and gauge theory Feynman diagrams.

Abstract:
We study the string modes in the pp-wave light-cone string field theory. First, we clarify the discrepancy between the Neumann coefficients for the supergravity vertex and the zero mode of the full string one. We also repeat our previous manipulation of the prefactor for the string modes and find that the prefactor reduces to the energy difference of the cos modes minus that of the sin modes. Finally, we discuss off-shell three-string processes.