Objective We aimed to compare the clinical outcomes of intravenous urography-assisted fluoroscopy-guided shockwave lithotripsy for radiolucent ureteral stones and standard shockwave lithotripsy for radiopaque ureteral...Objective We aimed to compare the clinical outcomes of intravenous urography-assisted fluoroscopy-guided shockwave lithotripsy for radiolucent ureteral stones and standard shockwave lithotripsy for radiopaque ureteral stones.Methods We retrospectively reviewed 734 patients with ureteral stones treated by fluoroscopy-guided shockwave lithotripsy between March 2014 and March 2021.The primary outcome was a stone-free rate with one session within 30 days,defined as no residual stones without auxiliary treatment.The multivariate analysis was used to examine whether the intravenous urography use predicted treatment success.Furthermore,we compared the outcomes using propensity score matching.Results Ninety-eight patients underwent the intravenous urography use protocol(Group I),and the remaining 636 patients underwent the non-intravenous urography protocol(Group N).Stone-free rates with one session within 30 days were 38%and 32%in groups I and N,respectively(p=0.3).No statistical differences were observed in the conversion rate to ureteroscopy(p=0.3)or complication rate(p=0.7)between Group I and Group N.One patient who developed skin redness was considered a complication of the contrast medium.Propensity score matching examined 88 matched pairs.Treatment success was obtained in 31(35%)patients in Group I and 33(38%)patients in Group N(p=0.9)within 30 days with one session.Conclusion Radiolucent stones can be safely and effectively treated by shockwave lithotripsy with intravenous urography.展开更多
This study provides new insights into the comparison of cable-stayed and extradosed bridges based on the safety assessment of their stay cables.These bridges are often regarded as identical structures owing to the use...This study provides new insights into the comparison of cable-stayed and extradosed bridges based on the safety assessment of their stay cables.These bridges are often regarded as identical structures owing to the use of inclined cables;however,the international standards for bridge design stipulate different safety factors for stay cables of both types of bridges.To address this misconception,a comparative study was carried out on the safety factors of stay cables under fatigue and ultimate limit states by considering the effects of various untoward and damaging factors,such as overloading,cable loss,and corrosion.The primary goal of this study is to describe the structural disparities between both types of bridges and evaluate their structural redundancies by employing deterministic and nondeterministic methods.To achieve this goal,three-dimensional finite-element models of both bridges were developed based on the current design guidelines for stay cables in Japan.After the balanced states of the bridge models were achieved,static analyses were performed for different safety factors of stay cables in a parametric manner.Finally,the first-order reliability method and Monte Carlo method were applied to determine the reliability index of stay cables.The analysis results show that cable-stayed and extradosed bridges exhibit different structural redundancies for different safety factors under the same loading conditions.Moreover,a significant increase in structural redundancy occurs with an incremental increase in the safety factors of stay cables.展开更多
The wind-induced vibration of stay cables of cable-stayed bridges, which includes rain-wind-induced vibration （RWIV） and dry galloping （DG）, has been studied for a considerable amount of time. In general, mechanic...The wind-induced vibration of stay cables of cable-stayed bridges, which includes rain-wind-induced vibration （RWIV） and dry galloping （DG）, has been studied for a considerable amount of time. In general, mechanical dampers or surface modification are applied to suppress the vibration. In particular, several types of surface-modification cable, including indentation, longitudinally parallel protuberance, helical fillet, and U-shaped grooving, have been developed. Recently, a new type of aerodynamically stable cable with spiral protuberances was developed. It was confirmed that the cable has a low drag force coefficient, like an indented cable, and that it prevented the formation of water rivulets on the cable surface. In this study, the stability for RWIV of this cable was investigated with various flow angles and protuberance dimensions in a wind-tunnel test. It was found that the spiral protuberance cable is aerodynamically stable against both RWIV and DG for all test wind angles. The effects of the protuberance dimensions were also clarified.展开更多
This paper presents the flutter derivatives （FDs） extracted from a stochastic system identification （SSI） method under different turbulent flows, The objective of the study is to investigate the effects of oncomin...This paper presents the flutter derivatives （FDs） extracted from a stochastic system identification （SSI） method under different turbulent flows, The objective of the study is to investigate the effects of oncoming turbulence on the flutter of suspended long-span bridges using a section model wind-tunnel test, Several wind-tunnel tests were performed on a truss bridge deck section with different oncoming turbulent properties involving reduced turbulence intensities and turbulent scales. This study includes an investigation of the effect of oncoming flows on modal dynamic responses. The transient and buffeting response data from the wind-tunnel test are analyzed using the system identification technique in extracting FDs, and the difficulties involved in this method are discussed. The time-domain SSI is applied to extract all FDs simultaneously from one and two degree-of-freedom （1DOF and 2DOF） systems, Finally, the results under different conditions are discussed and conclusions are formed.展开更多
Comparative studies of Japanese mythology have developed since the 1920s above all through eftbrts of Japanese ethnologists. They have paid attention to the possible ethno-cultural complexes that brought mythological ...Comparative studies of Japanese mythology have developed since the 1920s above all through eftbrts of Japanese ethnologists. They have paid attention to the possible ethno-cultural complexes that brought mythological motifs into the archipelago. In the present paper the theories set forth by Nobuhiro Matsumoto, Akihide Mishina, and Masao Oka are examined in terms of retrospect. The result shows that they shared the view that at least three different complexes, based in ancient Yamato, Izumo, and Kyushu respectively, contributed to the formation of Japanese mythology compiled in the 8th century CE （Common Era）. Their assumptions were synthesized by Taryo Obayashi in 1961, the hypothesis which has survived until today. In future we should cooperate with other disciplines and address the formation process of Japanese mythology.展开更多
The common vibration of cable caused by rain-wind combination has been known as most typical type and a lot kind of its countermeasures has been proposed for suppressing this phenomenon. Recently, stayed-cables were a...The common vibration of cable caused by rain-wind combination has been known as most typical type and a lot kind of its countermeasures has been proposed for suppressing this phenomenon. Recently, stayed-cables were also proved that they could be excited in dry state （without rain）, which is called dry-galloping. Recently, its mechanisms have been explained by axial flow, Reynolds number and so on. To clarify the characteristics of this galloping, wind tunnel test of a cable model with various kinds of wind angle was conducted. Then, three types of countermeasure were examined to suppress dry- galloping of bridge cable. The tests confirmed that the occurrence of dry-galloping depends on relative wind attacked angles and onset reduced wind speed. Furthermore, single spiral wire, double spiral wire and circular ring were found to have high effectiveness in mitigating this galloping when those are installed properly.展开更多
Wind-tunnel study on the improvement of aerodynamic stability of simplified suspension-bridge girder structures was conducted with using a 1/40-scaled section model. Objective of the study is the development of an eco...Wind-tunnel study on the improvement of aerodynamic stability of simplified suspension-bridge girder structures was conducted with using a 1/40-scaled section model. Objective of the study is the development of an economically superior suspension bridge with 500-1,000 m center span length. The wind-tunnel test showed that an edge-girder type cross section exhibited large amplitude torsional vortex-induced vibration as well as torsional flutter at a low wind speed. Accordingly, aerodynamic countermeasures of open grating deck and triangular fating, and structural countermeasures of center stay, diagonal bracing and mass increase were tried to improve the aerodynamic stability. Finally, feasibility of the best combination to a full-scale bridge was examined by structural analysis.展开更多
文摘Objective We aimed to compare the clinical outcomes of intravenous urography-assisted fluoroscopy-guided shockwave lithotripsy for radiolucent ureteral stones and standard shockwave lithotripsy for radiopaque ureteral stones.Methods We retrospectively reviewed 734 patients with ureteral stones treated by fluoroscopy-guided shockwave lithotripsy between March 2014 and March 2021.The primary outcome was a stone-free rate with one session within 30 days,defined as no residual stones without auxiliary treatment.The multivariate analysis was used to examine whether the intravenous urography use predicted treatment success.Furthermore,we compared the outcomes using propensity score matching.Results Ninety-eight patients underwent the intravenous urography use protocol(Group I),and the remaining 636 patients underwent the non-intravenous urography protocol(Group N).Stone-free rates with one session within 30 days were 38%and 32%in groups I and N,respectively(p=0.3).No statistical differences were observed in the conversion rate to ureteroscopy(p=0.3)or complication rate(p=0.7)between Group I and Group N.One patient who developed skin redness was considered a complication of the contrast medium.Propensity score matching examined 88 matched pairs.Treatment success was obtained in 31(35%)patients in Group I and 33(38%)patients in Group N(p=0.9)within 30 days with one session.Conclusion Radiolucent stones can be safely and effectively treated by shockwave lithotripsy with intravenous urography.
文摘This study provides new insights into the comparison of cable-stayed and extradosed bridges based on the safety assessment of their stay cables.These bridges are often regarded as identical structures owing to the use of inclined cables;however,the international standards for bridge design stipulate different safety factors for stay cables of both types of bridges.To address this misconception,a comparative study was carried out on the safety factors of stay cables under fatigue and ultimate limit states by considering the effects of various untoward and damaging factors,such as overloading,cable loss,and corrosion.The primary goal of this study is to describe the structural disparities between both types of bridges and evaluate their structural redundancies by employing deterministic and nondeterministic methods.To achieve this goal,three-dimensional finite-element models of both bridges were developed based on the current design guidelines for stay cables in Japan.After the balanced states of the bridge models were achieved,static analyses were performed for different safety factors of stay cables in a parametric manner.Finally,the first-order reliability method and Monte Carlo method were applied to determine the reliability index of stay cables.The analysis results show that cable-stayed and extradosed bridges exhibit different structural redundancies for different safety factors under the same loading conditions.Moreover,a significant increase in structural redundancy occurs with an incremental increase in the safety factors of stay cables.
文摘The wind-induced vibration of stay cables of cable-stayed bridges, which includes rain-wind-induced vibration （RWIV） and dry galloping （DG）, has been studied for a considerable amount of time. In general, mechanical dampers or surface modification are applied to suppress the vibration. In particular, several types of surface-modification cable, including indentation, longitudinally parallel protuberance, helical fillet, and U-shaped grooving, have been developed. Recently, a new type of aerodynamically stable cable with spiral protuberances was developed. It was confirmed that the cable has a low drag force coefficient, like an indented cable, and that it prevented the formation of water rivulets on the cable surface. In this study, the stability for RWIV of this cable was investigated with various flow angles and protuberance dimensions in a wind-tunnel test. It was found that the spiral protuberance cable is aerodynamically stable against both RWIV and DG for all test wind angles. The effects of the protuberance dimensions were also clarified.
文摘This paper presents the flutter derivatives （FDs） extracted from a stochastic system identification （SSI） method under different turbulent flows, The objective of the study is to investigate the effects of oncoming turbulence on the flutter of suspended long-span bridges using a section model wind-tunnel test, Several wind-tunnel tests were performed on a truss bridge deck section with different oncoming turbulent properties involving reduced turbulence intensities and turbulent scales. This study includes an investigation of the effect of oncoming flows on modal dynamic responses. The transient and buffeting response data from the wind-tunnel test are analyzed using the system identification technique in extracting FDs, and the difficulties involved in this method are discussed. The time-domain SSI is applied to extract all FDs simultaneously from one and two degree-of-freedom （1DOF and 2DOF） systems, Finally, the results under different conditions are discussed and conclusions are formed.
文摘Comparative studies of Japanese mythology have developed since the 1920s above all through eftbrts of Japanese ethnologists. They have paid attention to the possible ethno-cultural complexes that brought mythological motifs into the archipelago. In the present paper the theories set forth by Nobuhiro Matsumoto, Akihide Mishina, and Masao Oka are examined in terms of retrospect. The result shows that they shared the view that at least three different complexes, based in ancient Yamato, Izumo, and Kyushu respectively, contributed to the formation of Japanese mythology compiled in the 8th century CE （Common Era）. Their assumptions were synthesized by Taryo Obayashi in 1961, the hypothesis which has survived until today. In future we should cooperate with other disciplines and address the formation process of Japanese mythology.
文摘The common vibration of cable caused by rain-wind combination has been known as most typical type and a lot kind of its countermeasures has been proposed for suppressing this phenomenon. Recently, stayed-cables were also proved that they could be excited in dry state （without rain）, which is called dry-galloping. Recently, its mechanisms have been explained by axial flow, Reynolds number and so on. To clarify the characteristics of this galloping, wind tunnel test of a cable model with various kinds of wind angle was conducted. Then, three types of countermeasure were examined to suppress dry- galloping of bridge cable. The tests confirmed that the occurrence of dry-galloping depends on relative wind attacked angles and onset reduced wind speed. Furthermore, single spiral wire, double spiral wire and circular ring were found to have high effectiveness in mitigating this galloping when those are installed properly.
文摘Wind-tunnel study on the improvement of aerodynamic stability of simplified suspension-bridge girder structures was conducted with using a 1/40-scaled section model. Objective of the study is the development of an economically superior suspension bridge with 500-1,000 m center span length. The wind-tunnel test showed that an edge-girder type cross section exhibited large amplitude torsional vortex-induced vibration as well as torsional flutter at a low wind speed. Accordingly, aerodynamic countermeasures of open grating deck and triangular fating, and structural countermeasures of center stay, diagonal bracing and mass increase were tried to improve the aerodynamic stability. Finally, feasibility of the best combination to a full-scale bridge was examined by structural analysis.
