• Wind and Structures
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• v.17 no.6
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• pp.609-627
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• 2013

The Yingxian wooden tower in China is currently the tallest wooden tower in the world. It was built in 1056 AD and is 65.86 m high. Field measurements of wind speed and wind-induced response of this tower are conducted. The wind characteristics, including the average wind speed, wind direction, turbulence intensity, gust factor, turbulence integral length scale and velocity spectrum are investigated. The power spectral density and the root-mean-square wind-induced acceleration are analyzed. The structural modal parameters of this tower are identified with two different methods, including the Empirical Mode Decomposition (EMD) combined with the Random Decrement Technique (RDT) and Hilbert transform technique, and the stochastic subspace identification (SSI) method. Results show that strong wind is coming predominantly from the West-South of the tower which is in the same direction as the inclination of the structure. The Von Karman spectrum can describe the spectrum of wind speed well. Wind-induced torsional vibration obviously occurs in this tower. The natural frequencies identified by EMD, RDT and Hilbert Transform are close to those identified by SSI method, but there is obvious difference between the identified damping ratios for the first two modes.

• Korean Journal of Culture and Social Issue
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• v.25 no.4
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• pp.305-323
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• 2019

The Satisfaction With Life Scale (SWLS) is the most widely used instrument to measure life satisfaction. This study examined the factor structure and measurement equivalence of SWLS across age and gender in Korea. A total of 936 data were analyzed, comprising 433 college students (195 males and 238 females) and 503 middle-aged adults (237 males and 266 females). The results are as follows. Firstly, the data supported a modified single-factor model with correlations between error variances of items 4 and 5. Therefore, items 4 and 5 reflecting the past were found to share a distinct meaning with other items. Secondly, SWLS showed full strict invariance by gender, but only showed partial strict invariance between college students and middle-aged adults. These results indicate that meaningful comparisons of SWLS scores across gender may be valid, but careful attention should be paid when comparing age groups.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.1
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• pp.45-55
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• 2018

Concerns are emerging in marine industry on the additional fatigue damages induced by hydroelasticity, and large container carriers, among others, are considered to be susceptible to this hydroelastic response due to its large size, deck openings and high speed. This study focuses on the fatigue damage estimation of 9,400TEU container carrier based on the full scale measurement data via long-base strain gage installed on the ship. Some correlation analyses have been also done to check whether there was significant torsional response during the voyage. Direct cycle counting method was used to derive stress histogram and the long-term fatigue damage was estimated based upon that analyzed data. It turned out that the fatigue damage of this particular ship during the measurement period increased by more than 60% due to the hydroelastic response of the hull, and main contribution is considered to come from vertical bending mode.

• Smart Structures and Systems
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• v.10 no.4_5
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• pp.411-426
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• 2012

The Canton Tower (formerly named Guangzhou New TV Tower) of 610 m high has been instrumented with a long-term structural health monitoring (SHM) system consisting of over 700 sensors of sixteen types. Under the auspices of the Asian-Pacific Network of Centers for Research in Smart Structures Technology (ANCRiSST), an SHM benchmark problem for high-rise structures has been developed by taking the instrumented Canton Tower as a host structure. This benchmark problem aims to provide an international platform for direct comparison of various SHM-related methodologies and algorithms with the use of real-world monitoring data from a large-scale structure, and to narrow the gap that currently exists between the research and the practice of SHM. This paper first briefs the SHM system deployed on the Canton Tower, and the development of an elaborate three-dimensional (3D) full-scale finite element model (FEM) and the validation of the model using the measured modal data of the structure. In succession comes the formulation of an equivalent reduced-order FEM which is developed specifically for the benchmark study. The reduced-order FEM, which comprises 37 beam elements and a total of 185 degrees-of-freedom (DOFs), has been elaborately tuned to coincide well with the full-scale FEM in terms of both modal frequencies and mode shapes. The field measurement data (including those obtained from 20 accelerometers, one anemometer and one temperature sensor) from the Canton Tower, which are available for the benchmark study, are subsequently presented together with a description of the sensor deployment locations and the sensor specifications.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.139-146
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• 2017

PURPOSE: The purpose of this study was to systematically analyze the reliability and validity of the Korean-version of the balance assessment tools. METHODS: Two reviewers of this study independently evaluated the titles of articles and abstracts of studies published until December 2016 through electronic databases (RISS, NDSL, KISS, DBpia) using the keywords "Balance or posture or postural control or postural stability", "Test or assessment or measurement or outcome measure or assessment tool or measurement tool", "Korean version", "Reliability" and "Validity". Regarding the questions considered suitable for the purpose of this study, consensus was reached after reading the full text. Selecting journals suitable for the purpose of the study, they were analyzed as data. RESULTS: The reviewers selected nine papers suitable for the purpose of this study, and Korean-version of the balance assessment tools, included the Berg Balance Scale (BBS), Activities-specific Balance Confidence (ABC) scale, Postural Assessment Scale for Stroke (PASS), Motor Assessment Scale (MAS), Trunk Impairment Scale (TIS), Falls Efficacy Scale (FES), Tinetti-Balance scale, Fullerton Advanced Balance (FAB) scale, and Function In Sitting Test (FIST). Our study showed that the reliability and validity of the Korean-version of the balance assessment tools were high. CONCLUSION: The Korean-version of the balance assessment tools with high reliability and validity would enable physical therapists to make a more accurate evaluation of balance.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.4
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• pp.253-263
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• 2017

Regardless of whether it is acute or chronic, the assessment of pain should be simple and practical. Since the intensity of pain is thought to be one of the primary factors that determine its effect on a human's overall function and sense, there are many scales to assess pain. The aim of the current article was to review pain intensity scales that are commonly used in dental and oral and maxillofacial surgery (OMFS). Previous studies demonstrated that multidimensional scales, such as the McGill Pain Questionnaire, Short form of the McGill Pain Questionnaire, and Wisconsin Brief Pain Questionnaire were suitable for assessing chronic pain, while unidimensional scales, like the Visual Analogue Scales (VAS), Verbal descriptor scale, Verbal rating scale, Numerical rating Scale, Faces Pain Scale, Wong-Baker Faces Pain Rating Scale (WBS), and Full Cup Test, were used to evaluate acute pain. The WBS is widely used to assess pain in children and elderly because other scales are often difficult to understand, which could consequently lead to an overestimation of the pain intensity. In dental or OMFS research, the use of the VAS is more common because it is more reliable, valid, sensitive, and appropriate. However, some researchers use NRS to evaluate OMFS pain in adults because this scale is easier to use than VAS and yields relatively similar pain scores. This review only assessed pain scales used for post-operative OMFS or dental pain.

• Wind and Structures
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• v.14 no.3
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• pp.253-283
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• 2011

This paper presents the field measurement results of wind effects on a super-tall building (CITIC Plaza, 391 m high) located in Guangzhou. The field data such as wind speed, wind direction and acceleration responses were simultaneously and continuously recorded from the tall building by a wind and vibration monitoring system during two typhoons. The typhoon-generated wind characteristics including turbulence intensity, gust factor, peak factor, turbulence integral length scale and power spectral density of fluctuating wind speed were presented and discussed. The dynamic characteristics of the tall building were determined based on the field measurements and compared with those calculated from a 3D finite element model of the building. The measured natural frequencies of the two fundamental sway modes of the building were found to be larger than those calculated. The damping ratios of the building were evaluated by the random decrement technique, which demonstrated amplitude-dependent characteristics. The field measured acceleration responses were compared with wind tunnel test results, which were found to be consistent with the model test data. Finally, the serviceability performance of the super-tall building was assessed based on the field measurement results.

• International Journal of Concrete Structures and Materials
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• v.11 no.2
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• pp.377-389
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• 2017

Tests of the lateral and torsional stability are quite sensitive to the experimental conditions, such as support conditions and loading system. Controlling all of these conditions in a full-size test is a very challenging task. Therefore, in this paper, an experimental measurement method that can control the experimental conditions using a small-scale model was proposed to evaluate the lateral and torsional stability of beams. For this, a loading system was provided to maintain the vertical direction of the load applied to the beam, and a support frame was produced to satisfy the in-plane and out-of-plane support conditions. The experimental method using a small-scale model was applied successively to the lateral and torsional behavior and stability of I-shaped beams. The proposed experimental methods, which effectively accommodate the changes in the geometry and length of the beam, could contribute to further experimental studies regarding the lateral and torsional stability of flexural members.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.2
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• pp.91-111
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• 2024

Most of utility cable tunnels are constructed utilizing shield TBM as part of the underground transmission line project. The TBM chamber is the only space inside the tunnel that encounters rock and soil, and is the place with the highest frequency of accident exposure, such as collapse and collision accidents. Since there is currently no way to measure the disc cutter wear from outside the chamber, frequent inspection by workers is essential. Accordingly, in this study, in order to prevent safety accidents inside the TBM chamber and expect the effect of shortening the construction period by reducing the number of chamber openings, the concept of disk cutter wear measurement technology was established and a prototype was produced. By considering prior technology and determining that magnetic sensors are most suitable for the excavation environment, wear measurement sensor package were developed integrating magnetic sensors, wireless communication modules, power supply, external casing, and monitoring systems. To verify the performance of the prototype in an actual excavation environment, a full-scale tunnelling test was performed using a 3.6 m EPB shield TBM. Based on the full-scale tests, five prototypes were operated normally among eight prototypes. It was analyzed that sensor measurement, wireless communication, and durability performance were secured within a maximum thrust of 3,000 kN and a rotation speed of 1.5 RPM.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.32-41
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• 2009

In this study, scale-down design of full-scale Korean Utility Helicopter (KUH) main rotor blade has been investigated. The scaled model system were designed for the measurement of aerodynamic performance, tip vortex and noise source. For the purpose of considering the same aerodynamic loads, the Mach-scale method has been applied. The Mach-scaled model has the same tip Mach number, and it also has the same normalized frequencies. That is, the Mach-scaled model is analogous to full-scale model in the view point of aerodynamics and structural dynamics. Aerodynamic scale-down process could be completed just by adjusting scaling dimensions and increasing rotating speed. In the field of structural dynamics, design process could be finished by confirming the rotating frequencies of the designed blade with the stiffness and inertial properties distributions produced by sectional design. In this study, small-scaled blade sectional design were performed by applying domestic composite prepregs and structural dynamic characteristics of designed model has been investigated.