• Wind and Structures
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• 제35권5호
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• pp.309-322
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• 2022

Due to the complex terrain around high-speed railways, the windbreaks were established along different landforms, resulting in irregular windbreak transition regions between different subgrade infrastructures (flat ground, cutting, embankment, etc). In this paper, the effect of a windbreak transition on the wind flow around railways subjected to crosswinds was studied. Wind tunnel testing was conducted to study the wind speed change around a windbreak transition on flat ground with a uniform wind speed inflow, and the collected data were used to validate a numerical simulation based on a detached eddy simulation method. The validated numerical method was then used to investigate the effect of the windbreak transition from the flat ground to cutting (the "cutting" is a railway subgrade type formed by digging down from the original ground) for three different wind incidence angles of 90°, 75°, and 105°. The deterioration mechanism of the flow fields and the reasons behind the occurrence of the peak wind velocities were explained in detail. The results showed that for the windbreak transition on flat ground, the impact was small. For the transition from the flat ground to the cutting, the influence was relatively large. The significant increase in the wind speeds was due to the right-angle structure of the windbreak transition, which resulted in sudden changes of the wind velocity as well as the direction. In addition, the height mismatch in the transition region worsened the protective effect of a typical windbreak.

• 로봇학회논문지
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• 제17권2호
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• pp.142-151
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• 2022

With the advent of the 4th industrial revolution, autonomous driving technology is being commercialized in various industries. However, research on autonomous driving so far has focused on platforms with wheel-type platform. Research on a tracked platform is at a relatively inadequate step. Since the tracked platform has a different driving and steering method from the wheel-type platform, the existing research cannot be applied as it is. Therefore, a path-tracking algorithm suitable for a tracked platform is required. In this paper, we studied a path-tracking algorithm for a tracked platform based on a GPS sensor. The existing Pure Pursuit algorithm was applied in consideration of the characteristics of the tracked platform. And to compensate for "Cutting Corner", which is a disadvantage of the existing Pure Pursuit algorithm, an algorithm that changes the LAD according to the curvature of the path was developed. In the existing pure pursuit algorithm that used a tracked platform to drive a path including a right-angle turn, the RMS path error in the straight section was 0.1034 m and the RMS error in the turning section was measured to be 0.2787 m. On the other hand, in the variable LAD algorithm, the RMS path error in the straight section was 0.0987 m, and the RMS path error in the turning section was measured to be 0.1396 m. In the turning section, the RMS path error was reduced by 48.8971%. The validity of the algorithm was verified by measuring the path error by tracking the path using a tracked robot platform.

• 한국융합학회논문지
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• 제13권5호
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• pp.307-312
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• 2022

본 연구에서는 종아리 근육에 기능성 의류를 착용한 것이 종아리의 근기능에 어떤 영향을 미치는지 규명하고 기능성 의류가 종아리 근기능 증가에 활용가치가 있는지 검증하고자 하는데 그 목적이 있다. 연구의 대상은 하지에 이상이 없는 B 대학교의 남학생 21명을 대상으로 측정 하였다. 측정방법은 등속성근기능측정기인 CSMI사의 Humac Norm을 이용하여 오른쪽, 왼쪽 종아리에 기능성 의류 착용 전, 후 각속도 30°/sec, 120°/sec로 측정하였다. 피실험자들이 기능성 의류를 착용했을 때와 착용하지 않았을 때를 측정 해본 결과 발목 배측굴곡(Dorsi flexion)에서는 기능성 의류를 착용했을 때와 착용하지 않았을 때 유의한 차이가 나타나지 않았으나, 발목 저측굴곡(Plantar flexion)에서는 기능성 의류를 착용하였을 때 근력, 근파워, 근지구력이 유의하게 증가하는 것으로 나타났다. 따라서 종아리의 기능성 의류 착용이 운동기능 향상에 긍정적 효과가 있으며, 향후 연구에서는 대회를 앞두고 훈련을 하는 선수에게 기능성 의류를 착용한 인원과 착용하지 않은 인원의 근기능 향상정도를 비교해보는 연구를 제시하는 바이다.

• 대한정형도수물리치료학회지
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• 제29권1호
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• pp.81-93
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• 2023

Purpose: The current case study focuses on identifying the effects of manual therapy and home self-therapeutic exercise including on mouth opening and pain relief in patients with continuous neck pain with myofascial temporomandibular disorders (TMDs) accompanied by headache induced by masticatory myalgia Subjects: The study participant was a 27-year-old woman who was treated a year ago for pain related to TMDs accompanied by a headache. Methods: Manual therapy of the cervical spine with upper cervical spine posterior-to-anterior mobilization (C1~C2), upper cervical spine flexion mobilization (C0~C2), upper cervical spine lateral flexion mobilization (C0~C1), upper cervical spine thrust manual therapy (C1~C2) and manual therapy of the temporomandibular joint and muscles with transverse medial accessory temporomandibular joint mobilization, manual therapies for the temporal, the masseter, and medial pterygoid muscles were performed twice a week for about 30 minutes for 4 weeks. This protocol included 3 sessions in total. The home self-therapeutic exercise was to be performed two to three times a day. Results: The values more improved MMO increased to 41.4 mm, left masseter muscle PPT to 2.9 kgf/cm², right masseter muscle PPT to 3.1 kgf/cm², KHIT-6 to 46 points, neck pain intensity (by NRS) to 2 points, headache frequency to per weeks, cervical kyphotic angle to -8.06%, and GCPS to grade 1 (low-intensity pain without pain-related disorder). Conclusion: Manual therapy and home self-therapeutic exercise can be helpful for mouth opening and pain relief in patients with myofascial TMDs accompanied by secondary headaches induced by masticatory myalgia.

• 대한통합의학회지
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• 제11권2호
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• pp.207-219
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• 2023

Purpose : This study was conducted to investigate the changes in trunk movement and ground reaction during sit to stand motion using visual feedback. Methods : Fifteen adults (average age: 23.53±1.77 years) participated in this study. An infrared reflective marker was attached to the body each participant for motion analysis, and the participants performed sit to stand motion while wearing a hat attached with a laser pointer, which provided visual feedback. First, the sit to stand action was repeated thrice without obtaining any visual feedback, followed by a three minute break. Next, the laser pointers attached to hats were irradiated on a whiteboard, located at a distance of 5 m in front of the chairs, on which the participants sat; a baseline was set, and the participants performed stand up movements three times under this condition. A visual feedback was provided to the participants to prevent the laser pointers from crossing the set baseline. During each stand-up movement, the position of the reflective marker attached to the subject's body was recorded in real time using an infrared camera for motion analysis. The trunk movement and ground reaction force were extracted through recorded data and analyzed according to the presence or absence of visual feedback. Results : The results indicated that in the presence of a visual feedback during the sit-to-stand movements, the range of motion of the trunk and hip joints decreased, whereas that of the knee and ankle joints increased in the sagittal plane. The rotation angle of the trunk in the horizontal plane decreased. The left and right movement speed of the center of pressure increased, the pressing force decreased, and the forward and backward movement speed of the trunk decreased. Conclusion : The results suggest that the efficiency and stability of the stand up movement of a body increase when a visual feedback is provided.

• 한국전문물리치료학회지
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• 제30권3호
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• pp.184-193
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• 2023

Background: Studies investigating the immediate effects of a single intervention to correct forward head posture are rare. Objects: This study aimed to compare the changes in treatment effects in patients with forward head posture and neck pain after manual and self-exercise therapy over a 1-hour period. Methods: Twenty-eight participants were randomly divided into manual and self-exercise therapy groups. Following the initial evaluation, manual or self-exercise therapy was applied to each group for 30 minutes each in the prone, supine, and sitting positions. The variables measured were the craniovertebral angle (CVA), stress level, pain level, and sternocleidomastoid (SCM) stiffness. After the intervention, re-evaluation was conducted immediately, 30 minutes later, and 1 hour later. Two-way analysis of variance (ANOVA) was used to compare the maintenance of treatment effects between the two groups. Results: Based on the two-way mixed ANOVA variance, there was no interaction between the groups and time for all variables, and no main effects were found between the groups. However, a significant effect of time was observed (p < 0.05). Post hoc tests using Bonferroni's correction revealed that in both groups, the CVA, pain, and stress showed significant improvements immediately after the intervention compared with before the intervention, and these treatment effects were maintained for up to 1 hour after the treatment (p < 0.0083) in the manual therapy group. However, the stress level was maintained until 30 minutes later (p < 0.0083) in the self-exercise group. There was no significant decrease in right SCM stiffness before and after the intervention; however, left SCM stiffness significantly decreased after the self-exercise intervention (p < 0.0083). Conclusion: Both manual and self-exercise therapy for 30 minutes were effective in reducing forward head posture related to the CVA, pain, and stress levels. These effects persisted for at least 30 minutes.

• The Journal of Advanced Prosthodontics
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• 제15권6호
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• pp.302-314
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• 2023

PURPOSE. The aim of this study was to classify the shapes of retromolar pads and assess their morphometric differences using a 3D model. MATERIALS AND METHODS. Two hundred fully edentulous or Kennedy Class I partially edentulous patients (400 retromolar pads) were enrolled. Scan data of the definitive mandibular casts produced through functional impressions were obtained using a 3D laser scanner. Seven parameters (transverse diameter, longitudinal diameter, transverse-contour length, longitudinal-contour length, longitudinal/transverse diameter ratio, longitudinal/transverse-contour length ratio, and angle of the retromolar pad line to the residual alveolar ridge line) were measured using image analysis software. Subsequently, the pads were classified according to the shape. Statistical analyses were performed using 95% confidence intervals. RESULTS. Classifying the retromolar pads into three shapes led to high intra-examiner reliability (Cronbach's alpha = 0.933). The pear shape was the most common (56.5%), followed by oval/round (27.7%) and triangular (15.8%) shapes. There were no significant differences between the left and right sides according to the shape and no significant differences in any parameter according to age. The transverse diameter and longitudinal/transverse diameter ratio differed between sexes (P < .05). The triangular shape had a significantly different transverse diameter, transverse-contour length, longitudinal/transverse diameter ratio, and longitudinal/transverse-contour length ratio compared with the pear and oval/round shapes (P < .05). CONCLUSION. From a clinical reliability standpoint, classifying retromolar pads into three shapes (oval/round, pear-shaped, and triangular) is effective. The differences in the sizes among the shapes were attributed to the transverse measurement values.

• 로봇학회논문지
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• 제18권4호
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• pp.385-391
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• 2023

In the elderly population, sarcopenia occurs due to physical aging, leading to movement restrictions and loss of function. This results in dependence on daily activities and limitations in participation, ultimately decreasing the overall quality of life. In this study, we propose an algorithm designed to enable patients with sarcopenia to perform sit-to-stand and stand-to-sit movements seamlessly in their daily lives. The algorithm incorporates a wearable robot for muscle support and includes algorithms for standing and seated muscle strength support. To validate the algorithm's performance, EMG sensors were attached to the Rectus Femoris and Biceps Femoris muscles. The participants underwent two scenarios: one without wearing the device and one with the device providing muscle strength support, performing sit-to-stand and stand-to-sit motions for one minute in each case. The results showed a 16% increase in the EMG peak value of the Rectus Femoris muscle during standing motion (p=0.009). On the right side, there was a roughly 20% decrease (p=0.018) during standing and a 21% decrease (p=0.014) during sitting motion. In the future, we aim to gather additional data to further refine the algorithm. Our goal is to develop an optimal muscle strength support algorithm based on this data, making it applicable for real-life use by patients with sarcopenia.

• 한국음향학회지
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• 제26권2호
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• pp.87-94
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• 2007

LFM 신호를 이용한 능동소나 신호처리에서는 Split-beam을 이용한 좌우 두 빔 사이의 상호상관관계를 측정함으로써 표적의 자세각과 길이 정보를 추정할 수 있다. 그러나 탐지된 원거리 표적의 정보를 추정하기 위해서는 고분해능의 방위각 및 거리 해상도가 요구된다. 이를 위해 나이키스트(Nyquist) 샘플링 주파수보다 높은 샘플링 주파수가 필요하므로, 일반적으로 보간기법을 이용하여 과도샘플링(over-sampling) 을 해야 한다. 하지만 과도 샘플링된 좌우 빔신호를 이용하여 상호상관관계를 구할 경우, 요구되는 연산량과 메모리 용량이 일반적으로 상용 DSP 프로세서들의 처리용량과 내부 메모리 용량을 초과하게 되어 DSP를 이용한 실시간 구현이 어렵게 된다. 본 논문에서는 이러한 문제를 해결하기 위해 누적처리기법을 이용한 Split-beam처리 방법을 제안하였다. 제안한 기법의 성능을 모의실험을 통하여 검증하고, ADSP-TS101을 사용하여 실시간 시스템으로 구현하였다.

• 한국의류산업학회지
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• 제26권1호
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• pp.65-77
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• 2024

This study aimed to propose effective ways to integrate CLO into educational settings by conducting a comparative analysis of pattern functions in YUKA and CLO, specifically focusing on skirt prototypes and variations. CLO, being a 3D virtual sample CAD tool, is mainly used in education to facilitate the creation of 3D virtual clothing. In order to explore the applicability of CLO's pattern functions in pattern education, CAD education experts were asked to produce two types of skirt prototypes and two skirt variations. Subsequently, in-depth interviews were conducted. In addition, the skirt pattern creation process was recorded on video and used for comparative analysis of YUKA and CLO pattern functions. The comparison revealed that CLO provides the pattern tools necessary for drafting skirt prototypes. The learning curve for acquiring the skills necessary for drafting and transforming skirt prototypes was found to be relatively shorter for CLO compared to YUKA. In addition, due to CLO's surface-based pattern drawing method, it is difficult to move or copy only specific parts of the outline, and there are some limitations in drawing right angle lines. In the pattern transformation process, CLO's preview function proved to be advantageous, and it was highly rated on user convenience due to the intuitive UI. Thus, CLO shows promise for pattern drafting education and is deemed to have high scalability as it is directly linked to 3D virtual clothing.