This study examines the seismic vulnerability of non-structural components in high-rise buildings by proposing a normalized floor response spectrum (FRS) suitable for practical application. A Bayesian-mode-based method (BMBM) is used to develop the FRS, incorporating both modal amplification effects and the probabilistic variability observed across different building heights and story levels. The resulting spectrum is methodically compared with existing code-based and empirical methods to assess its consistency, conservatism, and relevance to engineering practices. The findings demonstrate that the proposed FRS provides a realistic yet reliable upper-bound estimate of floor accelerations, particularly in the upper stories where modal interactions are significant. This research offers a robust and practical framework for enhancing the seismic design of nonstructural components in vertical structures.

Atmospheric characterization has become a crucial area of study for exoplanets. The exoplanets known as ultra-hot Jupiters (UHJs) offer a natural laboratory for studying extreme atmospheric physics that cannot be observed in the solar system. One way to analyze their atmospheres is by transmission spectroscopy. However, it can be challenging to obtain such information because a planet’s signal is too weak compared to that of its host star, resulting in the planetary contribution to the observed spectrum being negligible. Therefore, the minimum observational requirements must be assessed first to distinguish the planetary signal from the stellar one to study these planets. In this context, we obtained the transmission spectra of UHJs TOI-1431 b and WASP-189 b by observing each exoplanet for one night with BOAO Echelle Spectrograph (BOES) on the 1.8 m telescope at Bohyunsan Optical Astronomy Observatory (BOAO). We searched for various chemical species by cross-correlating the exoplanetary spectra with model synthetic spectra. Our search for atmospheric signal returned a detection confidence level less than 3 σ for both targets. Therefore, we applied model injection to recover the atmospheric signals of the planets and assessed the minimum signal-to-noise ratio (S/N) to achieve 5 σ detection. During our search, we successfully recovered the planet signals with detection significances of 5.11 σ after a 750% injection of the model signal for TOI-1431 b and 5.02 σ for a 90% injection forWASP-189 b. These signal injection exercises suggest that a higher S/N of the transmission spectra is required to detect the planetary absorption features, and this can be done by stacking data from the observations of more than three cycles of the transit of a planet with a small-scale height such as WASP-189 b at BOAO facilities.

무작위진동이론(random vibration thoery, RVT)에 기반하여 원전 시설물 부계통의 지진응답해석과 확률론적 지진안전성평가를 위 한 구조응답스펙트럼(in-structure response spectrum, ISRS) 스케일링 기법을 새로이 제안한다. 새로운 방법은 대상 구조물의 동적 특 성에 대한 정보를 활용하지 않고, 구조응답과 지진지반운동의 파워스펙트럼밀도(power spectral density, PSD) 함수의 비를 사용한다. 무작위 진동의 첨두값 계수를 사용하여 진동의 PSD 함수로부터 첨두값의 통계적 특성과 무작위 진동의 응답스펙트럼을 추정할 수 있으므로, 반복계산을 통해 기존 지반운동 응답스펙트럼과 ISRS에 부합하는 PSD 함수와 그 비례계수를 도출한다. 이 계수를 신규 지 반운동 응답스펙트럼에 부합하는 PSD 함수에 적용하여, 신규 ISRS의 PSD 함수와 이에 대응하는 ISRS를 도출하는 스케일링을 수행 한다. 제안된 RVT에 기반한 새로운 스케일링 기법을 예제 원전 구조물에 적용하고, 응답이력방법에 의한 참조해와 비교하여 제안한 새로운 스케일링 기법이 정확성을 확인할 수 있다. 비례계수를 산정하기 위한 기존의 근사 방법들과 비교하여, 새로운 스케일링 기법 은 ISRS의 첨두 등을 잘 표현할 수 있는 것을 관찰할 수 있다.

We present the combined 2.5–30 μm spectra of four protostars acquired with the infrared camera and the infrared spectrograph on board the AKARI and Spitzer space telescopes, respectively. To analyze the ice absorption features in the 8–22 μm, we first performed a continuum determination process on mid-infrared spectra and applied a method to subtract the silicate absorption. We conducted a global fitting process to the absorption features in the combined infrared spectra using the experimental ice absorbance data to identify the intrinsic absorption of each ice component. We first derived the H2O ice column densities of both stretch and libration modes at 3.05 μm and 13.6 μm simultaneously. We also identified the absorption features containing NH3, CH3OH, CO2, and CO and decomposed their mixed components and compared their ice abundances at different evolutionary stages of the protostars. We explored possible absorptions of the organic ice species such as HCOOH, CH3CHO, and CH3CH2OH in the mid-infrared ranges. The ice analysis method developed in this study can be applied to the ice spectra obtained by the James Webb Space Telescope.

공력천칭기법 또는 풍압적분법에서 얻은 공력모멘트의 파워스펙트럼밀도는 종종 톱니 형상을 나타내며 의도 하지 않은 잡음원의 영향을 받을 수 있다. 이런 잡음은 고층건물의 실제 동적풍응답을 왜곡하여 부정확한 평가를 초래 할 수 있다. 따라서 고층건물의 바람으로 인한 응답을 정확하게 예측하기 위한 동적해석을 수행하기 전에 잡음을 걸러 내고 모달풍하중 스펙트럼을 평활화하는 것이 필수적이다. 본 연구에서는 잡음 및 스펙트럼 자료의 변동성을 최소화하 여 모달풍하중 스펙트럼의 정확성과 신뢰성을 높이기 위해 SSA(Singular Spectrum Analysis)를 활용한다. 모달풍하중 스펙트럼에 특화되고 수정된 SSA을 간략히 서술하고 쌍둥이 고층건물에 대해 구현해 보았다. 결과는 SSA가 효과적으 로 잡음을 줄이고 평활성을 향상하여 더 정밀하고 일관된 모달풍하중 스펙트럼을 활용할 수 있다. 이 방법은 다양한 풍 공학 분야에서 실험 및 해석의 성능을 향상하는데 유용할 것으로 판단된다.

Regulatory Guide (RG) 1.60 presents the response spectra for the seismic design, especially for the safe shutdown earthquake (SSE), of nuclear power plants. This guide is applicable to a two-step process involving the issuance of construction permits and operating licenses (10 CFR Part 50) as well as the issuance of combined construction and operating licenses (COLs), early site permits (ESPs), and standard plant design certifications (10 CFR Part 52) [1]. New reactor designs, however, require modified design response spectra (MDRS) by broadening the high-frequency range from design response spectra (DRS) in RG 1.60. In order to generate artificial time histories to meet the acceptable criteria described in NUREG-0800 [2], it9s necessary to develop the power spectral density of the MDRS. In this paper, we generate the artificial earthquake time histories of the MDRS for further research.

For important structures such as nuclear power plants, In-Structure Response Spectrum (ISRS) analysis is essential because it evaluates the safety of equipment and components installed in the structure. Because most structures are asymmetric, the response can be affected by eccentricity. In the case of seismically isolated structures, this effect can be greater due to the difference between the center of mass of the structure and the center of rigidity of the isolator layer. Therefore, eccentricity effects must be considered when designing or evaluating the ISRS of seismically isolated structures. This study investigated the change of the ISRS of an isolated structure by assuming accidental eccentricity. The variables that affect the ISRS of the isolated structure were analyzed to see what additional impact they had due to eccentricity. The ISRS of the seismically isolated structure with eccentricity was amplified more than when there was non-eccentricity, and it was boosted more significantly in specific period ranges depending on the isolator’s initial stiffness and seismic intensity. Finally, whether the displacement requirement of isolators can be applied to the variation of the ISRS due to eccentricity in the design code was also examined.