Background: Neck discomfort and movement limitations are common musculoskeletal problems among modern people. While cervical and thoracic joint mobilization are widely used interventions for cervical dysfunction, research comparing their immediate effectiveness in adults with asymmetrical cervical rotation is limited. Objectives: To compare the immediate effects of cervical versus thoracic joint mobilization in adults with adults with asymmetrical cervical rotation and discomfort. Design: Randomized controlled trial. Methods: Thirty adults with left-right differences in cervical rotation of more than 5 degrees were randomly assigned to a cervical mobilization group (CMG, n=15) or thoracic mobilization group (TMG, n=15). Both groups received Grade III mobilization for 15 minutes. Range of motion (ROM), pain (VAS), and neck disability index (NDI) were measured before and after intervention. Results: Both groups showed significant increases in ROM after intervention (P<.001). Within-group analysis revealed that the TMG showed significant pain reduction (P<.01) and significant reduction in left-right rotation asymmetry (P<.001), while the CMG showed improvement in ROM but no significant changes in asymmetry or pain (P>.05). Neither group showed significant changes in NDI. Between-group comparisons showed no significant differences in any outcome measures. Conclusion: Both cervical and thoracic joint mobilization increased cervical range of motion in adults with asymmetrical cervical rotation discomfort. The TMG demonstrated significant within-group improvements in left-right rotation asymmetry and pain reduction, suggesting potential clinical benefits of thoracic mobilization for certain aspects of cervical dysfunction.

A seismic intensity map, which describes ground motion distribution due to an earthquake, is crucial for disaster evaluation after the event. The ShakeMap system, developed and disseminated by the USGS, is widely used to generate intensity maps in many countries. The system utilizes a semi-variogram model to interpolate the measured intensities at seismic stations spatially. However, the default semi-variogram model embedded in ShakeMap is based on data from high seismic regions, which may not be suitable for the Korean Peninsula, categorized as a low-to-moderate seismic region. To address this discrepancy, this study aims to develop the region-specific semi-variogram model using local records and a region-specific ground motion model (GMM). To achieve this, we followed these steps: 1) collected records from significant earthquake events in South Korea, 2) calculated residuals between the observed intensities and predictions by the GMM, and 3) created semi-variogram models using weighted least squares regression to better fit short separation distances for PGA, PGV, SA0.2, and SA1.0. We compared the developed semi-variogram models with conventional models embedded in ShakeMap. Validation tests showed that the region-specific semi-variogram model reduced the mean squared error of intensity predictions by approximately 3.5% compared to the conventional model.

While the subduction zone earthquakes have long ground motion durations, the effects are also not covered in seismic design provisions. Additionally, the collapse risk of steel frame buildings subjected to long-duration ground motions from subduction earthquakes remains poorly understood. This paper presents the influence of ground motion duration on the collapse risk of steel frame buildings with special concentrically braced frames in chevron configurations. The steel buildings considered in this paper are designed at a site in Seattle, Washington, according to the requirements of modern seismic design provisions in the United States. For this purpose, the nonlinear dynamic analyses employ two sets of spectrally equivalent long and short-duration ground motions. Based on the use of high-fidelity structural models accounting for both geometric and material nonlinearities, the estimated collapse capacity for the modern code-compliant steel frame buildings is, on average, approximately 1.47 times the smaller value when considering long-duration ground motion record, compared to the short-duration counterpart. Due to the sensitivity to destabilizing P-Delta effects of gravity loads, the influence of ground motion duration on collapse risk is more profound for medium-to-high-rise steel frame buildings compared to the low-rise counterparts.

Being in a stable continental region (SCR) with a limited history of instrumentation, South Korea has not collected sufficient instrumental data for data-driven ground motion models. To address this limitation, we investigated the suitability of the hybrid ground motion simulation method that Graves and Pitarka (2010, 2015) proposed for simulating earthquake ground motions in South Korea. The hybrid ground motion simulation method used in this study relies on region-specific parameters to accurately model phenomena associated with the seismic source and the wave propagation. We initially employed relevant models and parameters available in the literature as a practical approach. We incorporated a three-dimensional velocity model developed by Kim et al. (2017) and a one-dimensional velocity model presented by Kim et al. (2011) to account for the crustal velocity structure of the Korean peninsula. To represent the earthquake source, we utilized Graves and Pitarka’s rupture generator algorithm along with a magnitude-area scaling relationship developed for SCR by Leonard (2014). Additionally, we assumed the stress and attenuation parameters based on studies of regional seismicity. Using the implemented platform, we simulated the 2016 Mw5.57 Gyeongju earthquake and the 2017 Mw5.4 Pohang earthquake. Subsequently, we compared results with recorded accelerations and an empirical ground motion prediction equation at strong motion stations. Our simulations had an overall satisfactory agreement with the recorded ground motions and demonstrated the potential of broadband hybrid ground motion simulation for engineering applications in South Korea. However, limitations remain, such as the underestimation of long-period ground motions during the 2017 Pohang earthquake and the lack of a model to predict the ground motion amplification associated with the near-surface site response accurately. These limitations underscore the importance of careful validation and refinement of region-specific models and parameters for practically implementing the simulation method.

Background: With the increasing demand for healthcare devices, the home healthcare market has been continuously expanding. Objectives: This study examined how a home calf massager affects muscle tone and stiffness in the calf region and the active range of motion (AROM) of the ankle in healthy adults to determine whether the massager is suitable for healthcare use in healthy individuals. Design: A quasi-experimental clinical trial. Methods: The study included 20 healthy men in their 20s, analyzing changes in muscle tone and stiffness in the calf region, AROM of the ankle joint, and differences between the two legs before and after applying the home calf massager. Results: After using the home calf massager, significant reductions in muscle tone and stiffness were observed in the lateral gastrocnemius muscles on both sides, as well as in the stiffness of the medial gastrocnemius muscles on both sides (P<.05). The AROM of the ankle joint significantly increased in all cases of dorsiflexion, plantar flexion, inversion, and eversion (P<.05). Conclusion: The use of a home calf massager in healthy adult males did not impose a physiological burden on muscle tone and stiffness in the calf region and was effective in immediately improving ankle joint mobility.

목적: 본 연구에서는 HMD VR을 사용하며 발생한 사이버 멀미와 멀미 민감성이 상관관계를 보이는지 알아보고자 하였다. 방법 : 건강한 젊은 성인 남녀 총 52명을 대상으로 VR 콘텐츠 이용 전 탈것에 대한 멀미 민감도를 측정하기 위 한 설문인 멀미 민감성 설문(Motion sickness susceptibility questionnaire)을 시행하였다. 광학 흐름 요소로 구 분한 두 가지 VR 콘텐츠를 선정하여 대상자에게 사용하도록 하고 사이버 멀미를 평가하기 위해 보편적으로 사용되 는 Simulator sickness questionnaire, SSQ 설문지를 통해 VR 콘텐츠 이용 전과 후의 사이버 멀미를 측정하였 다. VR 콘텐츠를 사용할 때 발생한 사이버 멀미와 피험자의 멀미 민감성에 대한 상관분석을 실시하였다. 결과 : VR 콘텐츠 A와 B를 사용 후 발생한 사이버 멀미와 멀미 민감성 상관분석에서 콘텐츠 A의 SSQ 요인 중 메스꺼움, 방향감각상실에서 유의한 상관관계를 보였다. 그중 메스꺼움 요인은 만 12세 이전 어린 시절, 최근 10년 간 성인 시절, 그리고 전체 멀미 민감성 항목 모두에서 유의한 상관관계가 나타났다. 반면 콘텐츠 B에서는 모든 항 목에서 유의한 상관관계를 보이지 않았다. 결론 : VR 콘텐츠를 사용하며 발생하는 사이버 멀미는 사용자에게 자기 움직임 착각을 유발하는 화면 구성 요 소가 많을 때 크게 나타났다. 두 콘텐츠 모두 게임을 진행할 때 전경의 움직임을 통해 플레이어의 이동 속도와 방 향을 가늠하게끔 구성되어있는데, 그중에서도 사용자의 평소 자세 움직임과 VR 환경에서 예상되는 자세 움직임이 일치하지 않은 콘텐츠에서 기존 멀미 민감성과 상관관계가 나타났다. 이를 분석하고 더 나아가 사이버 멀미를 저감 하기 위해서는 VR 콘텐츠의 시각적인 화면 구성 요소를 사용자들의 평소 움직임 패턴과 유사하게 제작하는 등 과 도한 vection을 제한할 필요성이 있다.

Background: Limited ankle dorsiflexion (DF) range of motion (ROM) is associated with mechanical dysfunctions and chronic ankle instability. Uphill treadmill walking exercise (UTWE) has the potential to improve ankle mobility and function. Objects: This study aimed to examine the immediate effects of a 15° UTWE on DF ROM and torque generation in patients with limited DF. Methods: The study included 20 adults, comprising 10 males and 10 females, with a mean age 28 years and a passive DF range of 5°–12°. After baseline assessments, participants completed 30 minutes of UTWE on a 15° incline treadmill, followed by post-assessments. DF ROM was evaluated during the stance phase of gait, and in both open-kinematic-chain (OKC) and closed-kinematic-chain (CKC) conditions using a goniometer and Image J software. DF and plantar flexion (PF) peak torque were measured with a Biodex Dynamometer. Results: Post intervention, maximum DF ROM during the stance phase of gait increased significantly from a mean of 8.54° ± 3.97° to 11.03° ± 4.41°. The DF ROM in the OKC and CKC conditions increased significantly from a mean of 8.90° ± 0.62° and 21.55° ± 0.72° to 18.00° ± 1.13° and 28.20° ± 1.00°, respectively (p < 0.0001). DF peak torque increased from 16.20 ± 1.28 N/m to 21.52 ± 1.39 N/m, and PF peak torque increased from 25.26 ± 2.51 N/m to 44.22 ± 4.20 N/m (p < 0.0002). Conclusion: UTWE significantly enhanced DF ROM and ankle torque, indicating that it may be an effective intervention for improving ankle function and preventing injury in clinical and rehabilitation settings.

Overloaded freight vehicles significantly contribute to road damage and increased maintenance costs, posing critical challenges for road management. This paper proposes an optimal decision-making methodology that incorporates the strategic behavior of road users into Weigh-In-Motion (WIM) enforcement strategies. The objective is to effectively derive optimal WIM installation locations while minimizing pavement maintenance costs and traffic congestion. The proposed framework consists of a bi-level optimization model. In the upper-level problem, decision-makers determine the optimal WIM installation locations within budget constraints. In the lower-level problem, drivers select routes to minimize their individual travel costs. The model integrates road management and travel costs to derive a balanced WIM installation strategy. Numerical experiments demonstrated that the proposed model identified WIM installation locations that effectively balanced the pavement management and travel costs. The results indicated that the proposed enforcement strategy can reduce pavement management costs while minimizing traffic congestion, thereby enhancing the overall efficiency of the transportation network. This paper provides a strategic foundation for reducing road damage and long-term maintenance costs by encouraging overloaded vehicles to comply with the legal weight limits. The proposed methodology serves as a practical guideline for WIM installation decision-making and policy development, contributing to the effective management of road networks.

Background: Thoracic kyphosis is a condition characterized by an excessive curvature of the thoracic spine, often leading to decreased trunk range of motion and various health complications. Objectives: This study aimed to investigate the effects of a rolling corrector on trunk range of motion (ROM) and thoracic kyphosis angle in individuals with thoracic kyphosis. Design: A randomized controlled trial. Methods: Thirty participants with a thoracic kyphosis angle of 40 degrees or more were randomly assigned to either the rolling corrector group (RCG) or the control group (CG). The RCG used the rolling corrector for 30 minutes per session, five times a week for two weeks, while the CG received no intervention. Trunk ROM and thoracic kyphosis angle were measured before and after the intervention. Results: The RCG showed significant improvements in trunk flexion, extension, lateral flexion, and rotation ROM, as well as in the thoracic kyphosis angle, in within-group comparisons (P<.05). The CG did not exhibit significant changes in any of these variables (P<.05). Significant differences between the RCG and CG were observed in trunk ROM and thoracic kyphosis angle (P<.05). Conclusion: The rolling corrector was effective in improving trunk ROM and reducing the thoracic kyphosis angle in individuals with thoracic kyphosis. These findings suggest that the rolling corrector may be a beneficial intervention for managing thoracic kyphosis.

최근 딥러닝은 자기공명영상 검사에서의 화질 개선을 위해 다양하게 활용되고 있다. 하지만 다양한 자기공명영상 검사에서 딥러닝이 적용된 기법과 상황에 대한 평가는 부족한 편이다. 이에 본 연구에서는 모션 ACR(American College of Radiology) 팬텀을 활용하여 일반적인 상황과 움직이는 상황에서 T2-PROPELLER(periodically, rotated overlapping parallel lines with enhanced reconstruction, PROPELLER)와 T2-FSE(fast spin echo, FSE) 기법의 화질을 비교 평가해 보고자 하였다. 연구 결과 움직이지 않는 상황에서의 딥러닝 프로세스를 적용하였을 때 유의미한 신호대잡음비와 대조대잡음비의 상승을 보였다. 하지만 팬텀에 움직임을 주는 동적인 상황 에서 딥러닝 프로세스를 적용하였을 때 유의미한 화질 개선을 보이지 않았다. 이러한 결과는 딥러닝 프로세스를 절대 적으로 사용하기보다 다양한 상황에 맞게 선택적으로 적용하는 것이 필요할 것으로 사료된다.

The damage to structures during an earthquake can be varied depending on the frequency characteristics of seismic waves and the geological properties of the ground. Therefore, considering such attributes in the design ground motions is crucial. The Korean seismic design standard (KDS 17 10 00) provides design response spectra for various ground classifications. If required for time-domain analysis, ground motion time series can be either selected and adjusted from motions recorded at rock sites in intraplate regions or artificially synthesized. Ground motion time series at soil sites should be obtained from site response analysis. However, in practice, selecting suitable ground motion records is challenging due to the overall lack of large earthquakes in intraplate regions, and artificially synthesized time series often leads to unrealistic responses of structures. As an alternative approach, this study provides a case study of generating ground motion time series based on the hybrid broadband ground motion simulation of selected scenario earthquakes at sites in the Nakdonggang delta region. This research is significant as it provides a novel method for generating ground motion time series that can be used in seismic design and response analysis. For large-magnitude earthquake scenarios close to the epicenter, the simulated response spectra surpassed the 1000-year design response spectra in some specific frequency ranges. Subsequently, the acceleration time series at each location were used as input motions to perform nonlinear 1D site response analysis through the PySeismoSoil Package to account for the site response characteristics at each location. The results of the study revealed a tendency to amplify ground motion in the mid to long-period range in most places within the study area. Additionally, significant amplification in the short-period range was observed in some locations characterized by a thin soil layer and relatively high shear wave velocity soil near the upper bedrock.

무용 교육은 연습실에서 교육자가 특정한 자세를 시범적으로 보여 주고 피교육자는 이를 따라서 동작하는 방식으 로 진행된다. 교육자는 특정한 자세를 모사할 때 동작에 대한 설명과 더불어 해당 동작에서 표현해야 하는 감성적인 상황을 설명하여 무용수가 해당 상황을 상상하고 동작하도록 유도한다. 이러한 교육은 무용 예술이 단순히 특정 자 세와 움직임을 정확하게 표현하는 것 이상으로 감성적인 움직임이 중요하기 때문에 동작에 감성이 포함될 수 있는 설명을 하는 것이다. 하지만 인간의 상상력은 개인마다 다르고 특히 아동 청소년은 경험의 부족으로 이미지 심상을 떠올리는데 다소 제한적일 수 있다. 이러한 제한적인 상황에서 피교육자는 몸으로 표현해야 할 감성적인 상황보다는 움직임과 자세에만 집중하게 되어 다소 건조한 표현을 하게 되거나 표현해야 하는 감성과는 다른 상황을 표현하게 된다. 본 연구는 무용수가 동작 별로 느껴야 하는 감성을 공간 그래픽으로 투사하여 몰입을 도와주며 자신의 움직임 이 실시간으로 공간 그래픽에 투영되어 감성적 몸의 움직임을 유도할 수 있는 인터랙티브 콘텐츠 연구이다. 연습실 공간에 가상의 콘텐츠가 프로젝션 되어 무용수는 자신이 연습실에 있는 것이 아닌 특정 동작을 위한 가상공간에 있 는 것처럼 구현된다. 또한, 설치되어있는 모션트레킹 센서(Motion Tracking Sensor)가 무용수의 신체와 움직임을 인 식하여 실시간으로 무용수의 움직임을 가상공간 그래픽에 파티클 이팩트(Particle Effect)를 통하여 표현해주므로 서 자신이 표현해야 하는 움직임에 동기를 유발한다. 이러한 감성 몰입을 위한 인터랙티브 콘텐츠 연구는 무용수의 상 상으로만 의존되어왔던 감성 몰입에 도입부 역할을 하며 또 다른 감성으로의 전이가 용이하도록 도와준다. 본 연구 는 단계별로 진행하며 각각의 단계마다 교육 현장에서 시행하여 교육적 효과를 실시간으로 검증한다. 이러한 단계별 진행을 통하여 검증된 결과를 기반으로 다음 단계의 연구자료로 활용하며 콘텐츠의 양적 확장과 이전 단계에서 발견 된 문제점을 개선한다. 본 연구를 통하여 유아 청소년의 감성발달과 움직임을 통한 신체적 건강에 이바지하며 인터 랙티브 콘텐츠를 통한 교육 방법의 방향성을 제시하고자 한다.

Accurate seismic vulnerability assessment requires high quality and large amounts of ground motion data. Ground motion data generated from time series contains not only the seismic waves but also the background noise. Therefore, it is crucial to determine the high-pass cut-off frequency to reduce the background noise. Traditional methods for determining the high-pass filter frequency are based on human inspection, such as comparing the noise and the signal Fourier Amplitude Spectrum (FAS), f2 trend line fitting, and inspection of the displacement curve after filtering. However, these methods are subject to human error and unsuitable for automating the process. This study used a deep learning approach to determine the high-pass filter frequency. We used the Mel-spectrogram for feature extraction and mixup technique to overcome the lack of data. We selected convolutional neural network (CNN) models such as ResNet, DenseNet, and EfficientNet for transfer learning. Additionally, we chose ViT and DeiT for transformer-based models. The results showed that ResNet had the highest performance with R2 (the coefficient of determination) at 0.977 and the lowest mean absolute error (MAE) and RMSE (root mean square error) at 0.006 and 0.074, respectively. When applied to a seismic event and compared to the traditional methods, the determination of the high-pass filter frequency through the deep learning method showed a difference of 0.1 Hz, which demonstrates that it can be used as a replacement for traditional methods. We anticipate that this study will pave the way for automating ground motion processing, which could be applied to the system to handle large amounts of data efficiently.

Background: Various intervention methods are being used to treat subacromial impingement syndrome. However, there is a lack of research on intervention using manual therapy and kinesiotaping together. Objectives: To investigated the effect of subacromial impingement syndrome on the mobilization with kinesiotaping. Design: A quasi-experimental clinical trial. Methods: An experiment was conducted by allocated twenty-nine patients with shoulder impingement syndrome to the mobilization with kinesiotaping group (MKG, n=15) and the kinesiotaping group (KG, n=14). The intervention of MKG and KG was conducted 3 times a week for 6 weeks. The outcome was The Shoulder Pain and Disability Index (SPADI) and range of motion (ROM). The collected data was analyzed using the SPSS ver. 21.0 program by paired t-test and independent t-test. Results: After the intervention, MKG had significant improvements in SPADI pain, SPADI disability, external rotation and internal rotation in MKG. However In KG, there was no significant decrease in SPADI pain, SPADI disability, external rotation and internal rotation. And in MKG, there was a statistically significant decrease in SPADI pain, SPADI disability and increase in external rotation and internal rotation. Conclusion: The mobilization with kinesiotaping was effective in improving pain, disability, and ROM in patients with subacromial impingement syndrome.

본 연구에서는 노인의 건강 증진 및 건강 유지를 위해 노인 맞춤형 운동 애플리케이션 개발을 목표로, 스마트폰을 활용한 실시간 동작 추적 기술과 영상과 사진을 바탕으로 한 AI 학습을 통 해 단계별 동작 인식과 판단이 가능한 운동 동작 모델을 구현하였다. 노인 맞춤형 운동 애플리 케이션은 실시간 피드백을 지원하고, 노인의 운동 능력과 신체 가동 범위에 적합하게 단계적 운동이 가능하도록 구현되어야 할 것이다. 이를 위해 본 논문에서는 골포스트 스퀴즈(Goal Post Squeeze) 운동 동작을 대상으로 하여 이를 일련의 단위 동작으로 설계하고, MoveNet 포 즈 추정 기법을 기반으로 동작 인식 모델을 개발하였다. 구현한 운동 동작 모델에 대한 작동 실험 결과 단계별 데이터 인식과 판단, 정동작과 오동작 판단, 수평유지를 판단하고 이를 바탕 으로 사용자에게 실시간 피드백을 제공할 수 있음을 확인하였다.

Recent earthquakes in Korea, like Gyeongju and Pohang, have highlighted the need for accurate seismic hazard assessment. The lack of substantial ground motion data necessitates stochastic simulation methods, traditionally used with a simplistic point-source assumption. However, as earthquake magnitude increases, the influence of finite faults grows, demanding the adoption of finite faults in simulations for accurate ground motion estimates. We analyzed variations in simulated ground motions with and without the finite fault method for earthquakes with magnitude (Mw) ranging from 5.0 to 7.0, comparing pseudo-spectral acceleration. We also studied how slip distribution and hypocenter location affect simulations for a virtual earthquake that mimics the Gyeongju earthquake with Mw 5.4. Our findings reveal that finite fault effects become significant at magnitudes above Mw 5.8, particularly at high frequencies. Notably, near the hypocenter, the virtual earthquake’s ground motion significantly changes using a finite fault model, especially with heterogeneous slip distribution. Therefore, applying finite fault models is crucial for simulating ground motions of large earthquakes (Mw ≥ 5.8 magnitude). Moreover, for accurate simulations of actual earthquakes with complex rupture processes having strong localized slips, incorporating finite faults is essential even for more minor earthquakes.

Background: Limitations of shoulder range of motion (ROM), particularly shoulder internal rotation (SIR), are commonly associated with musculoskeletal disorders in both the general population and athletes. The limitation can result in connective tissue lesions such as superior labrum tears and symptoms such as rotator cuff tears and shoulder impingement syndrome. Maintaining the center of rotation of the glenohumeral joint during SIR can be challenging due to the compensatory scapulothoracic movement and anterior displacement of the humeral head. Therefore, observing the path of the instantaneous center of rotation (PICR) using the olecranon as a marker during SIR may provide valuable insights into understanding the dynamics of the shoulder joint. Objects: The aim of the study was to compare the displacement of the olecranon to measure the rotation control of the humeral head during SIR in individuals with and without restricted SIR ROM. Methods: Twenty-four participants with and without restricted SIR ROM participated in this study. The displacement of olecranon was measured during the shoulder internal rotation control test (SIRCT) using a Kinovea (ver. 0.8.15, Kinovea), the 2-dimensional marker tracking analysis system. An independent t-test was used to compare the horizontal and vertical displacement of the olecranon marker between individuals with and without restricted SIR ROM. The statistical significance was set at p < 0.05. Results: Vertical displacement of the olecranon was significantly greater in the restricted SIR group than in the control group (p < 0.05). However, no significant difference was observed in the horizontal displacement of the olecranon (p > 0.05). Conclusion: The findings of this study indicated that individuals with restricted SIR ROM had significantly greater vertical displacement of the olecranon. The results suggest that the limitation of SIR ROM may lead to difficulty in rotation control of the humeral head.