• Clinics in Shoulder and Elbow
• /
• v.13 no.1
• /
• pp.146-152
• /
• 2010

Purpose: The purpose of this article was to review the effectiveness of arthroscopic debridement and tuberoplasty, and to evaluate the clinical and radiologic results of our series for irreparable massive rotator cuff tears in the elderly. Materials and Methods: We reviewed articles that focused on the treatment options and decision making for irreparable massive rotator cuff tears. In particular, we summarized the reported results of arthroscopic debridement and tuberoplasty for irreparable massive rotator cuff tears in the elderly. Among consecutive patients who had arthroscopic tuberoplasty for irreparable massive rotator cuff tears in our series, thirty-two patients available for clinical and radiological evaluation at a mean follow-up of 29 months (range, 13-52 months) were enrolled and reviewed for the analysis. Results: At the last follow-up, the range of active forward flexion increased significantly with excellent pain relief and improvement in the ability to perform the activities of daily living. However, the group with less than 2 mm in preoperative acromiohumeral distance showed inferior postoperative results. Conclusion: Arthroscopic tuberoplasty may be an alternative option in irreparable massive rotator cuff tears for pain relief and improvement of range of motion. However, good results can not be expected if the acromiohumeral distance is less than 2 mm preoperatively and decreases postoperatively, or when the preoperative range of motion is less than $90^{\circ}$ on flexion and abduction.

• Journal of Broadcast Engineering
• /
• v.17 no.3
• /
• pp.519-528
• /
• 2012

Voice activity detection (VAD) is generally conducted by extracting features from the acoustic signal and a decision rule. The performance of such VAD algorithms driven by the input acoustic signal highly depends on the acoustic noise. When video signals are available as well, the performance of VAD can be enhanced by using the visual information which is not affected by the acoustic noise. Previous visual VAD algorithms usually use single visual feature to detect the lip activity, such as active appearance models, optical flow or intensity variation. Based on the analysis of the weakness of each feature, we propose to combine intensity change measure and the optical flow in the mouth region, which can compensate for each other's weakness. In order to minimize the computational complexity, we develop simple measures that avoid statistical estimation or modeling. Specifically, the optical flow is the averaged motion vector of some grid regions and the intensity variation is detected by simple thresholding. To extract the mouth region, we propose a simple algorithm which first detects two eyes and uses the profile of intensity to detect the center of mouth. Experiments show that the proposed combination of two simple measures show higher detection rates for the given false positive rate than the methods that use a single feature.

• The Journal of the Korean bone and joint tumor society
• /
• v.3 no.1
• /
• pp.18-25
• /
• 1997

Prosthetic replacement is one of the most common methods of reconstruction after resection of malignant tumor around the knee. Gait analysis provides a relative objective data about the gait function of patients with prosthesis. The purpose of this study was to compare the gait pattern of the patients who underwent limb salvage surgery with prosthesis for distal femur and that of patients with prosthesis for proximal tibia. This study included ten patients (4 males, 6 females, mean age 22.7 years, range 14-36) who underwent a wide resection and Kotz hinged modular reconstruction prosthesis replacement and six normal adult(Control). The site of bone tumor was the distal femur (Group 1) in six patients and proximal tibia (Group 2) in 4 patients. The follow-up period ranged from 15 to 82 months (mean : 33 months). The evaluation consisted of clinical assessment, radiographic assessment, gait analysis using VICON 370 Motion Analysis System. The gait analysis included the linear parameters such as, walking velocity, cadence, step length, stride length, stance time, swing time, single support and double support time and the three-dimensional kinematics (joint rotation angle, velocity of joint rotation) of ankle, knee, hip and pelvis in sagittal, coronal and transverse plane. For the kinetic evaluation, the moment of force (unit: Nm/kg) and power (unit: Watt/kg) of ankle, knee and hip joint in sagittal, coronal and transverse plane. In the linear parameters, cadence, velocity, step time and single support were decreased in both group 1 and group 2 compared with control. Double support decreased in group 2 compared with control significantly(p<.05). In contrast to our hypothesis, there was no significant difference between group 1 and group 2. In Kinematics, we observed significant difference (p<.05) of decreased knee flexion in loading response (G2

• Journal of the Korea Computer Graphics Society
• /
• v.26 no.3
• /
• pp.9-19
• /
• 2020

With the recent development of various kinds of virtual reality devices, there has been an active research effort to increase the sense of reality by recognizing the physical behavior of users rather than by classical user input methods. Among such devices, the Leap Motion controller recognizes the user's hand gestures and can realistically trace the user's hand in a virtual reality environment. However, manipulating an object in virtual reality using a recognized user's hand often causes the hand to pass through the object, which should not occur in the real world. This study presents a way to build a visual feedback system for enhancing the user's sense of interaction between hands and objects in virtual reality. In virtual reality, the user's hands are examined precisely by using a ray tracing method to see if the virtual object collides with the user's hand, and when any collision occurs, visual feedback is given through the process of reconstructing the user's hand by moving the position of the end of the user's fingers that enter the object through sign distance field and reverse mechanics. This enables realistic interaction in virtual reality in real time.

• Journal of The Korean Association For Science Education
• /
• v.30 no.6
• /
• pp.799-814
• /
• 2010

This study aimed at developing a set of question cards for fostering deep understanding and encouraging reasoning about fossils and analyze the characteristics of visitors' communication depending on whether to use the question cards in a fossil gallery. Through several steps, a card set consisted of nine generic questions about fossil exhibitions and guidance for using question cards were developed. Data related to visitors' communications were collected from 18 peer groups (from 5th to 9th grade) visiting the fossil gallery of Gwacheon National Science Museum. Visiting groups' interactions were videotape recorded and transcribed. 'Holding time,' the types of 'actions,' and the types of 'conversation' were analysed. Visitors' actions were divided into three categories: ‘look’, 'speech', and 'motion.' Furthermore, visitors' conversations categorized as 'speech' were subdivided into four patterns: 'enumerative,' 'consensual,' 'responsive,' and 'argumentative.' Using the question cards contributes to increase holding time and most of the visiting actions. Most of the conversation patterns also increased except the responsive pattern. In conclusion, using question cards in a fossil gallery could facilitate concentrated and meaningful visits by enhancing active verbal and non-verbal communications between exhibit and visitor or among visitors, encouraging visitors' reasoning about exhibits, and guiding visitors what and how to focus on exhibits.

• Cartoon and Animation Studies
• /
• s.36
• /
• pp.619-641
• /
• 2014

Animation is an important tool to establish the identity of mutually related countries, as cultural contents with the economic value. That is, it is necessary that the Korean animation should extend the previous boundary of exchange, for the status of representative cultural industry in the 21st century global market. Especially, to overcome the regionally prejudiced and unbalanced cultural exchange, the possibility of extension with Czech animation, which has not had an active exchange with Korea, will be considered and the efficient method will be proposed. The Czech Republic is geopolitically located in the center of Europe and its infrastructure like industrial construction, investment environment, human resources is outstanding among Visegrad Group. The Czech Republic has a remarkable cultural border-crossing phenomenon, and as a complex country of cultural and religious characteristics of eastern and western European, it is a powerful nation leading Central Europe. Therefore, the animation exchange of Czech and Korea is valuable in culture and economy of both nations. Through such an animation exchange of both nations, not only Korean animation secures the diversity of exchange but also insignificant cultural exchange after formal establishment of diplomatic relations in 1990, will be revitalized and international firm relationship of both nations will be established. Therefore, as an activation plan or cultural exchange of Korea and the Czech Republic, concrete plan like Stop Motion Animation Workshop is proposed.

• Journal of Korean Society of Neurocognitive Rehabilitation
• /
• v.10 no.2
• /
• pp.27-34
• /
• 2018

The purpose of this study is to investigate the effect of task training for cognitive activation of upper extremity on upper limb function and activities of daily living and to suggest intervention in rehabilitation treatment. From January to February of 2018, nine stroke patients were arbitrated 30 minutes a day, five days a week, for four weeks. For the experimental group, the therapist has induced the group using the linguistic guidance to patients, so they utilize the cognition strategy. The control group conducted active exercises in a range of motion using the instruments and passive exercises in a range of motion to reduce the stiffness of joints and upper limbs. As muscle strengthening exercises, the patients were assigned to work on the biceps muscle of arm, triceps muscle of arm, and deltoid according to the individual patient's muscular strength level. For the experimental group, the MBI was improved by ten points at maximum, and K-AMPS motor skills showed the improvements of 1.0 logit at maximum, and processing skills showed improvements of 0.6 logits at maximum. In MFT, the maximum improvement was by two points. For the control group, MBI was improved by five points at maximum, and 0.2 maximum improvements were shown in K-AMPS' motor skills and 0.3 maximum improvements in processing skills. MFT showed no change. The conclusion is that the challenges to enable training for stroke patients give a positive impact on upper limb function and activities of daily living.

• Clinics in Shoulder and Elbow
• /
• v.26 no.4
• /
• pp.357-365
• /
• 2023

Background: The purpose of this study was to evaluate the effect of concomitant open distal clavicle excision (DCE) on postoperative clinical outcomes and incidence of acromial and scapular stress fractures (ASFs) in patients with symptomatic acromioclavicular joint osteoarthritis (ACJ OA) undergoing reverse total shoulder arthroplasty (RTSA). Methods: A single-surgeon retrospective cohort study was conducted including patients who underwent primary elective RTSA with or without DCE from 2015 to 2019 with a minimum 6-month follow-up period. Shoulder active range of motion (AROM) and visual analog scale (VAS) pain were recorded preoperatively and postoperatively. ASFs and other adverse events were identified using postoperative notes and/or radiographs. Characteristics and outcomes were compared between the RTSA and RTSA-DCE groups. Results: Forty-six RTSA patients (mean age, 67.9±8.7 years; 60.9% male; mean follow-up, 24.9±16.6 months) and 70 RTSA-DCE patients (mean age, 70.2±8.9 years; 20.0% male; mean follow-up, 22.7±12.9 months) were included. There were no significant intergroup differences in rates of ASF (RTSA, 0.0% vs. RTSA-DCE, 1.4%; P=1.00), stress reactions (RTSA, 8.7% vs. RTSA-DCE, 11.4%; P=0.76), reoperation, revision, or infection (all P>0.05), or in pre-to-postoperative reduction in VAS pain (P=0.17) at latest follow-up. However, the RTSA-DCE group had greater pre-to-postoperative improvement in flexion AROM (RTSA, 43.7°±38.5° vs. RTSA-DCE, 59.5°±33.4°; P=0.03) and internal rotation (IR) AROM (P=0.02) at latest follow-up. Conclusions: Concomitant DCE in RTSA improves shoulder flexion and IR AROM, alleviates shoulder pain, and does not increase the risk of ASFs. Level of evidence: III.

• Journal of Navigation and Port Research
• /
• v.37 no.3
• /
• pp.257-262
• /
• 2013

A ship operating in rough sea may suffer from an undesirable motion which may severely degrade the performance of equipment onboard and give a person an uncomfortable feeling. Hence, roll stabilization received a considerable attention and various devices including bilge keels, stabilizing fins, gyroscopic, anti-rolling tanks, rudders and flaps have been conceived and utilized for the purpose. The Coanda effect is evident when a jet stream is applied tangential to a curved surface of a hydrofoil since then the jet increases the circulation around the foil and consequently the lift. Model tests and numerical simulation have been conducted to examine the practicality of a fixed type fin stabilizer augmented by the Coanda jet. The results show that the lift coefficient of the modified Coanda fin at the zero angle of attack identically coincides with that of the original fin at ${\alpha}=\26^{\circ}$ when Coanda jet is supplied at the rate of $C_j$ = 0.25. It is also shown that fixed type fin stabilizers for active control of the motions of ships and the other mobile units without rotation can be put to practical use if the Coanda effect is applied.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.4
• /
• pp.247-254
• /
• 2013

In this paper, dynamic response analysis of a heave compensation system is performed for offshore drilling operations based on multibody dynamics. With this simulation, the efficiency of the heave compensation system can be virtually confirmed before it is applied to drilling operations. The heave compensation system installed on a semi-submersible platform consists of a passive and an active heave compensator. The passive and active heave compensator are composed of several bodies that are connected to each other with various types of joints. Therefore, to carry out the dynamic response analysis, the dynamics kernel was developed based on mutibody dynamics. To construct the equations of motion of the multibody system and to determine the unknown accelerations and constraint forces, the recursive Newton-Euler formulation was adapted. Functions of the developed dynamics kernel were verified by comparing them with other commercial dynamics kernels. The hydrostatic force with nonlinear effects, the linearized hydrodynamic force, and the pneumatic and hydraulic control forces were considered as the external forces that act on the platform of the semi-submersible rig and the heave compensation system. The dynamic simulation of the heave compensation system of the semi-submersible rig, which is available for drilling operations with a 3,600m water depth, was carried out. From the results of the simulation, the efficiency of the heave compensation system were evaluated before they were applied to the offshore drilling operations. Moreover, the calculated constraint forces could serve as reference data for the design of the mechanical system.