• Journal of the Society of Naval Architects of Korea
• /
• v.33 no.2
• /
• pp.127-138
• /
• 1996

The strip method, unified theory and 3-D panel method are commonly used methods for the seakeeping analysis of high-speed vessels. The strip method which is basically 2-dimensional method is known to give incorrect hydrodynamic coefficients and motion responses for the cases of high speed and low frequency region. And the unified theory which uses two dimensional approach in inner domain and slender body theory in outer domain is very complicate in computational modelling. Though the 3-D panel method requires comparatively long computation time, it is believed that the method gives good results without any limitation in ship speed and range of frequency for computation. In the 3-D panel method the source singularity representing translating and pulsating Green function is used and Hoff's method is adopted for the numerical calculation of the Green function. The computation time can be reduced by using the symmetry relationship with respect to longitudinal axis. In this paper the strip method and the 3-D panel method are compared for the seakeeping analysis of a high-speed catamaran. The Compared items are the hydrodynamic coefficients, wave exciting forces, frequency response functions and short-term responses in irregular waves.

• Journal of the Korean Arthroscopy Society
• /
• v.3 no.1
• /
• pp.24-29
• /
• 1999

Purpose : The purpose of this paper is to analyze the clinical results after meniscal repair using meniscal arrow. Materials and Methods : Between May 1997 and Aug 1998, we repaired 22 tom menisci in 22 patients using meniscal arrows. There were nineteen males and three females with an average age of 27 years. There were longitudinal tear in 14 cases, Bucket-handle tear were 7 cases and horizontal tear was in 1 case. In 22 meniscus tears, 16 cases were associated with anterior cruciate ligament tear. Average number of meniscal arrow that was used were 2.5(ranged 1 to 4). Average follow-up period was 14.7 months(ranged 6 to 22 months). We evaluated the clinical results by the Tapper and Hoover's grading system. Results : There were excellent in 16 cases, good in 4 cases and fair in 2 cases on the clinical results. At the last follow up, the range of the motion of the knee joint were average 135 degrees(ranged 125 to 140 degrees). Mean time elapsed for meniscal repair were 25 minutes(ranged 15 to 40 minutes). Conclusion : Meniscal arrow has many advantages such as short operative time, easy fixation technique, and less neurovascular injury. We think that arthroscopic meniscal repair using meniscal arrow is effective treatment method in selected patient who have longitudinal, bucket-handle tear at the posterior hom associated with anterior cruciate ligament tear.

• Physical Therapy Korea
• /
• v.15 no.2
• /
• pp.54-63
• /
• 2008

The purpose of this study was to examine the effect of the hip internal rotation on knee extensor and hip abductor electromyographic (EMG) activity during stair up and stair down mobility. Eighteen healthy subjects were recruited. All subjects performed stair up and down movements on a step of 30cm height while maintaining the hip in neutral (condition 1) and hip in internal rotation (condition 2). Surface EMG activity was recorded from five muscles (gluteus maximus, vastus lateralis (VL), vastus medialis oblique (VMO), posterior gluteus medius (Gmed), and tensor fascia latae (TFU)) and hip internal rotation angle was measured using a three dimensional motion analysis system The time period for stair up and down was normalized using the MatLab 6.5 program, and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). The EMG activities according to the hip rotation (neutral or internal rotation) during the entire time period of stair up and down in each phase were compared using a paired t-test. During the entire period of stair up, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). During the entire period of stair down, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). However, the EMG activities of the other muscles were not significantly different between the conditions (p>.05). These results suggest that the stair up and down maintaining hip internal rotation was could be a contributing factor on patellar lateral tracking.

• Journal of Acupuncture Research
• /
• v.31 no.4
• /
• pp.109-119
• /
• 2014

Objectives : The aim of this study is to observe clinical characteristics and treatment outcomes of inpatients admitted to a Korean medicine hospital for shoulder pain based on magnetic resonance imaging(MRI) findings. Methods : 28 patients with MRI data were included. Data on MRI findings, duration of pain, and treatment effects were collected. To measure treatment outcomes, verbal numerical rating scale(VNRS), range of motion(ROM), and a clinical condition grading system were used. Results : 1. The patient population was 75.0 % female and 39.3 %(n=11) belonged to the 51~60-year-old age group. In the under 40 population, 1 or less MRI findings were found. 2. As for the type of disorder, 82.1 % of the patients were diagnosed with 'Supraspinatus lesion', 39.3 % with 'subacromial-subdeltoid(SA-SA) bursitis', and 28.6 % with 'Adhesive capsulitis' 3. Numerous correlations could be made between duration of pain and MRI findings. 'rotator cuff full thickness tear' was more prevalent in acute shoulder pain patients, and 'Adhesive capsulitis' in chronic patients. 4. VNRS and ROM at the time of discharge had significantly improved as compared to VNRS and ROM at the time of admission. 5. As for correlation between MRI findings and clinical condition grade, patients diagnosed with 'rotator cuff partial tear' reported to be in 'good' condition or better whereas those with 'rotator cuff full thickness tear' reported to be in 'fair' condition or worse. Conclusions : Patients admitted to a Korean Medicine hospital for shoulder pain had varying degrees of severity as shown on MRI. Almost all lesions responded well to Korean medicine treatment.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.3
• /
• pp.53-61
• /
• 2012

This paper proposes a real-time distance measurement system of high temperature and high speed target using infrared stereo camera. We construct an infrared stereo camera system that measure the difference between target and background temperatures for automatic target measurement. First, the proposed method detects target region based on target motion and intensity variation of local region using difference between target and background temperatures. Second, stereo matching by left and right target information is used to estimate disparity about real-time distance of target. In the proposed method using infrared stereo camera system, we compare distances in three dimension trajectory measuring instrument and in infrared stereo camera measurement. In this experiment from three video data, the result shows an average 9.68% distance error rate. The proposed method is suitable for distance and position measurement of varied targets using infrared stereo system.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.5
• /
• pp.361-366
• /
• 2017

As the recent development of computing architecture and application software technology, real world simulation, which is the ultimate destination of computer simulation, is emerging as a practical issue in several research sectors. In this paper, metal plate motion in a square shock tube for small time interval was calculated using a supercomputing-based fluid-structure-combustion multi-physics simulation tool called Illinois Rocstar, developed in a US national R amp; D program at the University of Illinois. Afterwards, the simulation results were compared with those from experiments. The coupled solvers for unsteady compressible fluid dynamics and for structural analysis were based on the finite volume structured grid system and the large deformation linear elastic model, respectively. In addition, a strong correlation between calculation and experiment was shown, probably because of the predictor-corrector time-integration scheme framework. In the future, additional validation studies and code improvements for higher accuracy will be conducted to obtain a reliable open-source software research tool.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.3
• /
• pp.353-359
• /
• 2020

In this study, the controller structure and control algorithm of medical robot bed developed for pressure ulcer prevention and healing are described. The existing pressure ulcer prevention mattress is operated manually and the remaining maximum body pressure exceeds the pressure of ulcer generation, so there is always room for pressure ulcers. However, the system developed in this study does not generate the pressure ulcers because the body pressure drops to zero when the keyboard of the bed descends using the active electric driving keyboard. In addition, even if the bed is raised and the pressure above the critical body ulcer pressure is abnormal, the device and the control algorithm are designed so that the lasting time is within the pressure ulcer generation critical time and the pressure ulcer itself is not generated. The bed key board motor is a motor designed with the BLDC servos suitable for medical use and these can communicate each other easily through CAN(Car Area Network). The system is new medical robot bed that is effective in preventing pressure ulcers and will be distributed to many patients suffering from pressure ulcers.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.20 no.2
• /
• pp.217-225
• /
• 2007

This paper proposes the real-time hybrid shaking table testing methods to simulate the dynamic behavior of a soil-structure interaction system with dynamic soil stiffness by using only a structure model as the physical specimen and verifies their effectiveness for experimental implementation. Experimental methodologies proposed in this paper adopt such a way that absolute accelerations measured from the superstructure and shaking table are feedback to the shaking table controller, and then the shaking table is driven by the calculated motion of the absolute acceleration (acceleration feedback method) or the absolute velocity (velocity feedback method) of foundation that is required to simulate the dynamic behavior of a whole soil-structure interaction system. The shaking table test is implemented by reflecting the dynamic soil stiffness, which are differently approximated from the theoretical one depending on the feedback methods, on the shaking table controller to calculate soil part. The effectiveness of the proposed experimental methods is verified by comparing the response measured from the test on a foundation-fixed structural model and that obtained from the experiment of a soil-interaction system under the consideration in this paper and by matching the dynamic soil stiffness reflected on the shaking table controller with that identified using the experimentally measured data.

• Journal of Digital Convergence
• /
• v.15 no.8
• /
• pp.333-340
• /
• 2017

Timelapse is an imaging technique that captures motion at regular intervals and then projects it at normal speed. We looked at Timelapse advertising images of global brands and presented a model for analyzing components and expression methods of Timelapse, a new image technique. In previous research, literature research, Internet data survey, and YouTube data were investigated. Continuous photography has been developed as an imaging technique, and we have examined the current production status applied to domestic and foreign documentary, domestic and foreign drama, film, and advertisement. In 2015-2016, I will analyze the techniques of iPhones (2016), Ralph Lauren Polo Ads (2015), and Canon EOS (2013) videos that use Timelapse techniques in their recent advertisements. The results show that the Timelapse component is a static element, the static motif is mainly an artificial structure, the place is outdoor, the color is taken at a time showing the characteristics of the place, and the layout is all centered. The dynamic motif is a moving object. The dynamic line consists of a story based on the object. The time is about 11-15 seconds, the longest is about 1 minute and 30 seconds, and the editing is mainly focused on the product with the brand logo emphasized. In conclusion, it is the role of the image to pay attention to the advertisement and catch the eye. In order to motivate the buyer's mind, it is necessary to direct and edit such as Timelapse, which stimulates the emotions inherent in the mind and stimulates the non-verbal symbols. Future research is likely to reveal various attempts at temporal editing of images.

• Clinics in Shoulder and Elbow
• /
• v.6 no.1
• /
• pp.72-79
• /
• 2003

Purpose: To compare the results of arthroscopic rotator cuff repair and subacromial decompression in partial thickness rotator cuff tear (PTRCT) with those in full thickness rotator cuff tear (FTRCT). Subjects and method: Of the 46 patients who were rested of the rotator cuff tear based on the operational findings, 42 patients who were able to receive a serial follow-up for 2 years were selected as the study subjects. The average age of the patients at the time of the operation was 55 years, and the mean duration of the follow-up was 34 months. The subjects included 22 cases of PTRCT and 20 cases of FTRCT. In terms of rotator cuff repair, the average number of tendon to tendon repair (TTR) was 1 in both PTRCT and FTRCT, and that of tendon to bone repair (TBR) was 1 and 3 in PTRCT and FTRCT, respectively. The average number of use of suture anchor was 1 and 2 in PTRCT and FTRCT, respectively. The level of shoulder pain and function of the subjects were measured using shoulder functional evaluation score of American shoulder and elbow society (ASES score) at before and 2 years following the operation. Results: At the final follow-up following the operation, PTRCT group showed changes in scores from 7.2 to 0.9 on average pain score and 34 to 91 on ASES score, whereas FTRCT group showed changes in scores from 7.6 to 1.2 on pain score and 29 to 88 on ASES score. There were no significant differences between the two groups (P > 0.05). The average range of motion of shoulder significantly increased in both groups at the final follow-up in comparison with the pre-operative time point. The evaluation at the final follow-up showed that 93% of the total subjects showed good or excellent results, and 95％ showed satisfactory results from the procedure with regard to pain reduction and functional outcomes. Two cases of the 3 fair results were caused by acromioclavicular arthritis. Conclusion: It may be anticipated that arthroscopic rotator cuff repair and subacromial decompression may bring satisfactory post-operative outcomes in both PTRCT and FTRCT on pain relief and functional recovery. However, careful preoperative examination of the acromioclavicular joint is critical to avoid failures of these procedures.