• Journal of Korean Society of Steel Construction
• /
• v.22 no.5
• /
• pp.487-496
• /
• 2010

The structural damping ratios for seismic design of nuclear power plant structures are specified in Regulatory guide 1.61 of the United States NRC for RC structures of 4%(OBE) and 7%(SSE), and for steel structures of 3%(OBE) and 4%(SSE), but not for steel-plate concrete (SC) structures that have been developed recently. The objective of this study is to investigate the damping ratios of SC structures by identifying the relative differences in the damping ratios between RC and SC structures. An experimental study was performed on four specimens, RC-S, RC-M, SC-S and SC-M, where S stands for shear-governed and M for moment-governed. The conducted method was free vibration testing by rupturing a brittle steel plate that linked the actuator and the mass center. The test results were analyzed to determine fundamental frequencies and damping ratios at various load levels. By examining the relative differences in damping ratios of four specimens, it is proposed for SC structures to use the same damping ratio of 4% as RC one at OBE, but 1% less damping ratio than RC one resulting in 6% at SSE.

• Journal of Digital Convergence
• /
• v.18 no.8
• /
• pp.111-118
• /
• 2020

This study conducted an empirical analysis of SSE-listed companies to verify the effects of evaluation and disclosure of internal control systems on the agency costs management and controlling shareholders. Agency costs can affect the valuation of accounting information as asymmetry of information in the relationship between a company and its stakeholders, or induce financial costs as an adverse selection. If the firm's agency costs are reasonable, the valuation of the company can also move in a relatively positive direction. In this study, the evaluation information of the internal control system was analyzed through sales management ratio and equity ratio as substitute variables to analyze the relationship between management and agent costs of the controlling shareholders. In addition, independent control ratio, capital balance ratio, and company scale were used as control variables, as a result of the analysis, the evaluation information of internal control was found to be related to the agency costs of managers and governance structure. This study can be conducted to positive factors in evaluating the reliability and corporate value of accounting information according to the evaluation of internal control of SSE-listed companies and helps to understand the financial reporting environment.

• PNF and Movement
• /
• v.22 no.1
• /
• pp.55-70
• /
• 2024

Purpose: The purpose of this study was to investigate the effects of three relaxation techniques, namely, Static Stretching Exercise (SSE), Eccentric Contraction Exercise (ECE), and Suboccipital Muscle Release (SMR) on the flexibility and balance of the lower limb in adults with hamstring shortening. Methods: The participants were 45 adults in their 20s with hamstring shortening. They performed three exercises (i.e., SSE, ECE, and SMR) for two weeks. We measured flexibility, muscle tone and stiffness, proprioception, and balance before and after the intervention, applying each relaxation technique. Data were analyzed using two-way repeated measures analysis of variance (ANOVA). The significance level was set at α=0.05. Results: Flexibility increased in the SSE, ECE, and SMR groups, with the SSE group showing the greatest improvement. Muscle tone and stiffness decreased in all groups, with the ECE group exhibiting the highest reduction. Proprioception increased in the SSE, ECE, and SMR groups, with SSE demonstrating the greatest enhancement. Balance also increased in all groups, with the ECE group showing the most pronounced improvement. Conclusion: Overall, all three relaxation techniques for hamstring shortening resulted in improved flexibility, muscle tone and stiffness, proprioception, and balance of the lower limb in adults with hamstring shortening. The findings of this study underscore the importance of selecting an appropriate technique according to the purpose of treatment and the condition of the patient.

• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.369-378
• /
• 2023

Smilax sieboldii is one of the Smilax species. A number of Smilax plants have multiple physiologically-active components and anti-inflammatory/anti-oxidant effects. Antiobesity effects induced by Smilax sieboldii have not been reported. In this study, we investigated the effects and molecular mechanisms of anti-obesity activity of 70% ethanol Smilax sieboldii extract (SSE). The anti-obesity effect of SSE was determined using 3T3-L1 adipocytes. We confirmed that SSE was not cytotoxic to murine 3T3-L1 preadipocytes, we evaluated SSE dose-dependently decreased the accumulation of lipids via an Oil Red O assay and triglyceride assay. These anti-obesity activities of SSE were mediated by the inhibition of adipogenesis-related marker genes (peroxisome proliferator activated receptor-γ, CCAAT-enhancer-binding protein α, and SREBP1c) and lipogenesis-related marker genes (fatty acid synthase and aP2). These results suggest that SSE has the potential to exert anti-obesity and anti-hyperlipidemia effects by regulating adipogenic transcription factors and inhibiting the expression of adipogenic markers.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.1
• /
• pp.31-39
• /
• 2016

Hash function is a cryptographic primitive which conduct authentication, signature and data integrity. Recently, Wang et al. found collision of standard hash function such as MD5, SHA-1. For that reason, National Security Research Institute in Korea suggests a secure structure and efficient hash function, LSH. LSH consists of three steps, initialization, compression, finalization and computes hash value using addition in modulo $2^W$, bit-wise substitution, word-wise substitution and bit-wise XOR. These operation is parallelizable because each step is independently conducted at the same time. In this paper, we analyse LSH structure and implement it over SIMD-SSE, AVX and demonstrate the superiority of LSH.

• Atmosphere
• /
• v.24 no.3
• /
• pp.365-378
• /
• 2014

The limits of S-band dual-polarization radars in Korea are not reflected on the recent weather forecasts of Korea Meteorological Administration and furthermore, they are only utilized for rainfall estimations and hydrometeor classification researches. Therefore, this study applied four merging methods [SA (Simple Average), WA (Weighted Average), SSE (Sum of Squared Error), TV (Time-varying mergence)] to the QPE (Quantitative Precipitation Estimation) model [called RAR (Radar-AWS Rainfall) calculation system] using single-polarization radars and S-band dual-polarization radar in order to improve the accuracy of the rainfall estimation of the RAR calculation system. As a result, the merging results of the WA and SSE methods, which are assigned different weights due to the accuracy of the individual model, performed better than the popular merging method, the SA (Simple Average) method. In particular, the results of TVWA (Time-Varying WA) and TVSSE (Time-Varying SSE), which were weighted differently due to the time-varying model error and standard deviation, were superior to the WA and SSE. Among of all the merging methods, the accuracy of the TVWA merging results showed the best performance. Therefore, merging the rainfalls from the RAR calculation system and S-band dual-polarization radar using the merging method proposed by this study enables to improve the accuracy of the quantitative rainfall estimation of the RAR calculation system. Moreover, this study is worthy of the fundamental research on the active utilization of dual-polarization radar for weather forecasts.

• Journal of The Geomorphological Association of Korea
• /
• v.18 no.4
• /
• pp.261-270
• /
• 2011

This study is to describe morphological linear anomalies manifested in the geomorphological landscapes of Woongcheon river-basin, situated in the western ends of Charyong Mountainous Range, and to elucidate their morphotectonic significance. The order of decreasing valley scale in the study area is NE-SW, NNE-SSW, NNW-SSE, N-S, and E-W series. The valleys of NE-SW lineament appear as the largest in the study area, having piedmont slope, terraces, low-relif hills. NNE-SSW lineament cross obliquely the geomorphological elements of the precedent lineament. NNW-SSE, N-S and E-W lineament cut the forms of higher orders showing NE-SW and NNE-SSW lineament. Scale of the linear valleys is not correlated with the order of streams. It is paradoxal that great valleys are not associated with the rivers of highest order. It owes to adaption of regional discharge system along the valleys exploiting the fracture resulted from succeeding tectonic accidents.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.89-96
• /
• 2007

Finite failure NHPP models presented in the literature exhibit either constant. monotonic increasing or monotonic decreasing failure occurrence rates per fault. Accurate predictions of software release times. and estimation of the reliability and availability of a software product require quality of a critical element of the software testing process : test coverage. This model called Enhanced non-homogeneous Poission process(ENHPP). In this paper, exponential coverage and S-type model was reviewed, proposes modified(the superosition and mixture) model, which make out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method. model selection based on SSE statistics for the sake of efficient model, was employed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.09a
• /
• pp.67-74
• /
• 2001

This paper presents the Safe Shutdown Earthquake(SSE) input motion for the seismic design of the Advanced Power Reactor 1400(APR1400). The Design Ground Response Spectra(DGRS) far the SSE is based on the design spectrum specified in regulatory Guide(RG) 1.60 of U.S. Nuclear Regulatory Commission(US NRC), anchored to a Peak Ground Acceleration(PGA) of 0.3g and enriched in the high frequency range. This SSE seismic input motion is to be applied to the seismic analysis as the free-field seismic motion at the ground surface of both the rock and generic soil sites fur APRI1400. The enrichment for APR1400 seismic input motion is performed considering the current US NRC regulations, the seismic hazard studies performed by the Lawrence Livermore National Laboratory (LINL) and Electric Power Research Institute(EPRI) for the Central and Eastern United States nuclear power plant sites, and the seismic input motions used in the design certifications of the three existing U.S. advanced standard plants. It is represented by a set of DGRS and the accompanying Target Power Spectral Density(PSD) Function in both the horizontal and vertical directions.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.26 no.5
• /
• pp.552-558
• /
• 2016

A control rod drive mechanism(CRDM) is a reactor regulating system, which inserts, withdraws or maintains a control rod within a reactor core to control the reactivity of the core. The CRDM for Jordan Research and Training Reactor with 5MW power has been designed and fabricated based on the HANARO’s experience through KAERI and DAEWOO consortium. This paper describes the seismic test results to demonstrate the operability, the drop performance and the structural integrity of CRDM during or after seismic excitations. The seismic tests are carried out under 5 OBE and 1 SSE loads at three Test Rigs simulating the reactor structure and the pool top. From the tests, the CRDM is smoothly driven without a malfunction of stepping motor under OBE load. The pure drop time under OBE and SSE loads is measured as 1.169s and 1.855s to meet the design requirement. Also, it is found that the CRDM maintains the structural integrity without a change of the function and natural frequency before and after seismic loads.