• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.5
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• pp.175-188
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• 2009

Besides the passwords have low complexity, they can easily be revealed by the shoulder-surfing attack when they are inputted through the input devices such like keyboard. To overcome these problems, many new authentication schemes, which change the user secret different form or let users input their secrets through the more complex manners, have been suggested, but it is still hard to find the balanced point between usability and security. In this paper, we introduce a new authentication scheme that use the traditional alpha-numeric password as user secret based on operation of them on matrix. We show the security strength of our proposal through the analyses in the various aspects and confirm the difficulty that users feel from our proposal through the user study.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.95-99
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• 2013

We introduce arthroscopic Bankart repair technique using antegrade suture passer that can effectively restore detached anteroinferior capsulolabral complex for shoulder anterior instability. After diagnostic arthroscopy is performed using posterior, anteroinferior and anterosuperior portals, we confirm Bankart lesion and perform debridement and decortications of anteroinferior glenoid edge and neck. Suture anchor is inserted through anteroinferior portal at 2 mm medial side of glenoid edge (4:30 direction). Scorpion$^{TM}$ loaded suture is directly advanced to detached and retracted anteroinferior capsulolabral complex and the suture is passed at 10~15 mm medial side of detached anteroinferior capsulolabral complex (5:30 direction). The suture is retrieved by Scorpion's hook and then is tied using samsung medical center (SMC) sliding knot technique. Then suture anchors are serially inserted (2:30, 3:30) and capsulolabral complex repair is performed using suture hook and suttle-relay technique. This technique that can obtain anatomical restoration of anteroinferior glenohumeral ligament with proper tension is useful technique to reduce postoperative recurrence and makes it possible for less experienced surgeons.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.175-179
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• 2016

Recent advances in technology of medical image have made surgical simulation that is helpful to diagnosis, operation plan, or education. Improving and enhancing the medical imaging have led to the availability of high definition images and three-dimensional (3D) visualization, it allows a better understanding in the surgical and educational field. The Real human field of view is stereoscopic. Therefore, with just 2D images, stereoscopic reconstruction process through the surgeon's head, is necessary. To reduce these process, 3D images have been used. 3D images enhanced 3D visualization, it provides significantly shorter time for surgeon for judgment in complex situations. Based on 3D image data set, virtual medical simulations, such as virtual endoscopy, surgical planning, and real-time interaction, have become possible. This article describes principles and recent applications of newer imaging techniques and special attention is directed towards medical 3D reconstruction techniques. Recent advances in technology of CT, MR and other imaging modalities has resulted in exciting new solutions and possibilities of shoulder imaging. Especially, three-dimensional (3D) images derived from medical devices provides advanced information. This presentation describes the principles and potential applications of 3D imaging techniques, simulation and printing in shoulder and elbow practice.

• Korean Journal of Applied Biomechanics
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• v.28 no.3
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• pp.187-191
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• 2018

Objective: The purpose of the present study is to investigate the effect of a muscle activity by applying the complex exercise method of sling in accordance with the provision of various vibration intensities for paraplegia-spinal cord injury. Method: The subjects of the study were 15 men in their 40s and 50s with lower limb disabilities and low potential risk, who were randomly divided into a sling exercise group (SG n=4), a sling with low frequency vibration group (SLVG n=4), a sling with mid-frequency vibration group (SMVG n=4), and a sling with high frequency group (SHVG n=4) in accordance with the provision of slings and vibration stimuli. The vibratory intensity provided was divided into low frequency (30 Hz), mid-frequency (50 Hz), and high frequency (70 Hz). The anterior deltoid (AD), the posterior deltoid (PD), the pectoralis major (PM), the upper trapezius (UT), the latissimus dorsi (LD), and the multifidus (MF) were measured to compare and analyze muscle activity. Results: The closed kinetic chain (CKC) exercise to the shoulder joint showed higher muscle activity in most muscles for the SMVG, and statistically significant differences in the anterior deltoid (AD), the pectoralis major (PM), and the multifidus (MF) in particular. Conclusion: The intermediate frequency (50 Hz) string vibration was the effective vibration stimuli for Closed kinetic chain (CKC) exercises.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.229-235
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• 1992

The usefulness of a portable linear electronic scanner. B-mode ultrasonic machine, was evaluated for estimating the longissimus muscle area from ultrasonic measurement of the muscle depth in 22 live pigs. The electronic scanner was easy to operate for muscle measurements in live pigs, which did not have to be held but were caged. The cross-sectional images of longissimus muscle and covering muscles and fat appeared on the monitor with grey scale in real time. It was easy to identify the ultrasonograms of fat and muscular tissues because the images differed in the degree of the grey scale. The longissimus muscle had less echogenic image than the other muscles. The boundary lines between first, second or third layers of backfat and the longissimus muscle were distinct on the ultrasonogram. The ultrasonic measurement at the shoulder was not acceptable because of the unstable measurements and the complex tissue structure. The repeatabilities for the measurements of longissimus muscle depth at one-half body length and last rib were acceptable. The simple correlation coefficients between ultrasonic estimates of the muscle depth in live pigs and the actual areas in the carcass, were 0.50 and 0.55 at the last rib and the one-half body length, respectively. Therefore, those positions were similarly suitable to measure. The method of electronic scanner for determining longissimus muscle area from the muscle depth was suitable for practical use in the field because of the simple and inexpensive technique.

• PNF and Movement
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• v.4 no.1
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• pp.1-7
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• 2006

Objective : The purpose of this study was conducted to find scapular movement instability related with shoulder complex and provide strengthening the scapular muscles with proprioceptive neuromuscular facilitation(PNF). Methods : This is a literature study with books and articles, seminar note and book for PNF international course. Results : The scapular serve as the platform for humeral motions. The scapulothoracic articulation is stabilized and controlled, in part, by the scapular muscles. Therefore, if scapular muscle function is altered, then dysfunctional scapulothoracic kinematics may result. Strengthening exercise for scapular muscles are a common part of rehabilitation programs designed for patients with scapular instability. Conclusion : Treatment of the scapular instability is provided. It is that treatment with combination of isotonic, stabilize reversal on different patient's positions.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.84-91
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• 2007

Purpose: The aim of this study was to report seven cases of metallic radial head prosthesis and present the limit of use in Korea. Materials and Methods: Metallic radial head arthroplasty was performed on 7 patients between April 2006 and December 2006, who had complex elbow injury including comminuted radial head fracture. Indication, operative findings and outcome were assessed. Availability and payment of implant were investigated. Results: All of the patients had more than one associated injury including coronoid fracture, olecranoan fracture, and ligament ruptures. According to Mason classification, there were three type III and four type IV fractures. All radial head fractures were too comminuted to reconstruct. There were two excellent results, four good, and one poor, as graded by Mayo score. There were no patient with instability and implant related complications. Insufficient supply of implant did not enable to do scheduled surgery in 2 cases. Current medical insurance did not cover charge for radial prosthesis, five patients could not help paying for that by themselves. Conclusion: Metallic radial head implants are useful when the radial head cannot be repaired reliably. Preoperative preparing and coverage by medical insurance based on appropriate indication are helpful for decision for a treatment option.

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.140-145
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• 2011

Purpose: Installing a radial head prosthesis has developed into a reliable procedure to replace the native radial head for treating unreconstructible radial head fracture when this is associated with an unstable elbow or forearm. A variety of implants have been developed and these are now commercially available. This article reviews the literature related to the indications, the available implants and the surgical techniques of radial head replacement arthroplasty. Materials and Methods: The main indication for a metallic radial head prosthesis is a comminuted fracture that is not amenable to reconstruction, and particularly if it is associated with complex elbow injuries. Excision of the radial head should be avoided in the presence of combined injured ligaments or interosseous membrane injury. Three different implants are available in Korea, including the bipolar, press fit monopolar and loose fit monopolar radial head prostheses. A primary technical goal of radial head arthroplasty is the insertion of an implant that closely replicates the native radial head. The major pitfall when using a metallic radial head prosthesis is the insertion of a longer implant, which results in overstuffing of the radiocapitellar joint. Results and Conclusion: Satisfactory clinical results can be anticipated when a radial head prosthesis is used for the correct indications and when a systemic approach is undertaken to ensure proper sizing. For the future studies, we need data regarding the long term outcomes and comparison of the various types of prostheses.

• Clinics in Shoulder and Elbow
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• v.9 no.1
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• pp.50-59
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• 2006

Purpose: The nonoperative outcome of elbow dislocations with associated radial head and coronoid fractures are often unsatisfactory because of chronic instability and stiffness from proloned immobilization, Therefore we managed these injuries with well programed surgical appproaches. Method: Ten patients with this injury were evaluated retrospectively from May 1998 to June 2004 after a minimum of 12 months. These injuries include elbow dislocation and associated fractures of both the radial head and the coronoid process. All ten patients were treated by one clinic operatively with similar scheduled surgical methods which started on the lateral side and terminated on the medial side of the elbow. Radial head and neck fractures were classified Mason types, as two and three types respectively with six and four cases and six cases were fixated. Coronoid process were fixated with screws anteroposterior directly or anchor suture in all cases, each type was classified one, two and three. where were three type one, four type two, and three type three were according to Regan and Morrey classification. Results: The outcome was three resulting in excellent, four good, two normaland and the remaining case was one poor according to the Mayo Elbow Performance score. At a terminal follow up, the range of motion of the elbow averaged flection contracture, $6^{\circ}(0{\sim}20^{\circ})$ and further flection, $129^{\circ}(115{\sim}140^{\circ})$. Two patients had complications requiring additional care. One, displaced coronoid process which was repaired with capsule and the other patient experienced, palsy of ulnar nerve and contracted elbow joint. Conclusions: Usage of early operation as the minimum injury of medial ligaments complex and the rigid fixation of fractures to prompt motion with our scheduled management for elbow dislocations with associated radial head and coracoid fractures provided excellent results.

• Journal of the Korean Orthopaedic Association
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• v.54 no.4
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• pp.353-360
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• 2019

Purpose: In the treatment of Dupuytren's contracture, the aim of optical treatment is to lower the recurrence rate and reduce complications. This paper reports the results of subtotal fasciectomy in Dupuytren's contracture, extending the excision of palmar fascial structures from the diseased to normal appearing adjacent fascial structure. Materials and Methods: From 2007 to 2017, 45 patients with Dupuytren's contracture treated by subtotal fasciectomy were reviewed retrospectively. The mean follow-up period was 45.9 months. Ninety-two digits were involved (index: 2, middle: 10, ring: 44, little: 36). The predisposing factors and affected joint were reviewed and the preoperative and postoperative contracture was measured. For clinical results, quick disabilities of the arm, shoulder, and hand (quick DASH) were used. Complications, including wound or skin problems, nerve injuries, hematoma, and complex regional pain syndrome, were assessed. Results: Preoperative flexion contracture was 43.2° in the proximal interphalangeal joint and 32.9° in the metacarpophalangeal joint. In nine cases, patients had residual contracture of 9.7° (range, 5°-20°) on average and if the total number of cases were included, the mean residual contracture was 2.3° on average. The quick DASH score at the 12 months follow-up was 12.4. The overall complication rate was 26.6%. Conclusion: Subtotal fasciectomy can be a good surgical treatment option for Dupuytren's contracture with a low recurrence and low complication rate compared to other open procedures.