• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.1
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• pp.1-12
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• 2009

The purpose of this study is to discovered assessment items for improving athletic efficiency and management of golf courses. Through this, the study intended to provide basic data for creating competitive golf courses and management. Important assessment items were selected by inducing preliminary assessment items and conducting a preliminary survey and a main survey for specialists through a theoretical study. For the survey results studied, reliability and average value for importance were calculated using SPSS/PC Window Release 12.0. As assessment of importance by assessment area, in athletic efficiency assessment, course management level was the highest, followed by fairness of games and operation of games. In management assessment, importance of service level, information management, facility management, management of game assistants, etc. were high. As assessment of importance by assessment item, it was found that 'variety of golf shot' and 'the length of a course' were important in course layout. Also 'start interval among teams' and 'disturbance of play' were assessed as important items in game operation, while 'fair reservation' and 'rounding rotation time' were important in fairness of games. In addition, in information management, 'kind service of golf course staffs' and 'prompt reservation and notification' were found to be important assessment items. In facility management, all assessment indexes were over 4.0, which means all of them are important for quality of golf course and competitiveness. In membership service, 'appropriate price of goods for sale' and 'service for members' were relatively important assessment items. Further, in management of game assistants, 'qualifications and skillfulness of game assistants' was assessed as a very important index. Although the current study only selected important items to assess excellent golf courses, it is necessary to apply the study results to the actual sites and verify them for golf course both at domestic and abroad.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.9-16
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• 2013

Long term evolution (LTE) and LTE-Advanced (LTE-A) systems adopt closed-loop multiple-input multiple-output antenna techniques. Equal gain transmission which has equal gain property is the key factor in their codebook design. In this paper, a novel differential codebook structure which maintains the codebook design requirements of LTE or LTE-A systems. Especially, eight-phase shift keying (8-PSK) constellations are used as elements of codewords, which not only maintain equal gain property but also reduce the computation complexity of precoding and decoding function blocks. The equal gain property is very important to uplink because the performance of uplink is very sensitive to the peak-to-average power ratio (PAPR). Moreover, the operation of the proposed differential codebook is explained as a rotation-lock structure. As the results of computer simulations, the steady-state throughput performance of the proposed codebook shows at least 0.9dB of SNR better than those of the conventional LTE codebook with the same amount of feedback information.

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.86-91
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• 2004

Purpose: To evaluate the methods and results of the surgical treatment in the trimalleolar fracture of the ankle. Materials and Methods: We analysed the results of the ankle trimalleolar fracture which were treated with open reduction and internal fixation from January 1999 till September 2003. There were 45 patients who had at least six months follow up, 16 men, and 29 women. We have analysed the mechanism of injury, methods of operation and postoperative complications. Results: The results were assessed on ankle AP, lateral and mortise X-rays and retrospective chart review. There were 30 supination-external rotation, 13 pronation-external rotation, 2 pronation-abduction in the mechanism of injury by Lauge-Hansen classification. Cases of the posterior malleolar fracture which involved more than 25% of the weight bearing surface were 7 (15.6%). Medial malleolar mono-fixation was done in 5 cases, fibular mono-fixation in 2 cases, bimalleolar fixation in 32 cases, trimalleolar fixation in 6 cases. 38 cases (84.4%) were good or excellent in clincal assessment and 39 cases (86.7%) were good or excellent in radiological assessment according to the criteria of the Meyer. There was no difference of results among the surgical treatment methods. Conclusion: The results of our study indicate that the rigid fixation with early ankle motion and weight bearing is needed in ankle trimalleolar fracture. But minimal fixation is not bad in slight displaced fracture. Both anterior approach and posterior approach were useful methods to stabilization the posterior malleolar fracture. And pre-operative evaluation to detect the hidden soft tissue injuries and fracture mechanism is very important to avoid the failure.

• Clinics in Shoulder and Elbow
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• v.2 no.1
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• pp.53-59
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• 1999

Initial treatment of multidirectional instability of the shoulder would be a thorough rehabilitation program. If rehabilitation fails to resolve a patient's symptoms, the most commonly performed surgical procedure remains the inferior capsular shift. Eleven patients who had disabling multidirectional instability of the shoulder were managed with the inferior capsular shift. All of the procedure were performed by means of an anterior approach and a laterally based capsular shift. All of the patients were the contact athletes. The purpose of our study was to evaluate the efficacy of the inferior capsular shift procedure in the contact athletic patients, to review the loss of external rotation postoperatively and to discuss their return to sports. Mean follow up duration was 14.5 months(range, 12 to 24). Pain was relieved postoperatively in all cases and most patients could get stability except one case of recurrent subluxation. The average loss of external rotation and forward flexion after the operation were Y and 30 at last follow up. By the rating scale from American Shoulder and Elbow Society, overall scores improved from 49 points to 85 points. The results were excellent or good in 9 patients(82%) out of 11 patients. In reference to return to sports, 10 patients(91 %) of 11 patients returned to their sports with 7 patients (64%) returning at the same levels of competitiveness. The inferior capsular shift procedure was considered to be a recommendable method for the management of the multidirectional instability of the shoulder.

• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.90-92
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• 2008

Purpose: Congenital upper eyelid defect is rare anomaly whether it is compared with syndromic anomaly or not. It has many clinical manifestation in the extent, location. Many operation procedures such as simple closure, semicircular rotation flap, Cutler Beard procedure, lower lid rotation flap, etc can be used to reconstruct eyelid defects. We intend to introduce a simple, congenital eyelid defect which was not compared with syndromical anomaly, ophthalmic complication. Methods: Our experience is a case of 19 years old female who had a upper eyelid coloboma without any other anomalies. we could not find any skeletal deformity in orbital CT scan. she had no ophthalmic problem. we reconstructed the defect with bilateral marginal flap after deepithelization of supramarginal area and tarsal reposition. Results: There were no visible deformity of lid lining. postoperative scar was favorable. satisfactory results were obtained in cosmetic and functional aspects. Conclusion: Upper lid coloboma without other anomalies is rare. we obtained satisfactory outcome as treated this rare case with marginal flap advancement.

• Clinics in Shoulder and Elbow
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• v.5 no.1
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• pp.47-54
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• 2002

Purpose : We evaluated clinical result of arthroscopic and open Bankart repair in anterior shoulder instability to identify factors iuluencing operative result and prognosis. Materials & Methods . We reviewed 24 patients of anterior shoulder instability treated with arthroscopic Bankart repair in 16 cases and open Bankart repair in 8 cases. Average age was 26 years old and involved in dominant arm in 15 cases. Patients were suffered instability for 3.1 years before operation and mean follow-up was 2 year 9 months ( 1 you 9 months -4year 10 months). Results : Post operative pain was subsided in 2 weeks in arthroscopic surgery and 3 weeks in open surgery. The final range of motion after arthroscopic repair were flekion in 168" , external rotation in 54" , and internal rotation in 79, and after open repair 168" ,49" , and 78 respectively. In arthroscopic surgery,2 cases (13%) were redislocated, and 4 cases(25%) showed mild instability. In open case,1 case (11%) showed mild instability. According to function- al result by Rowe grading scale, satisfactory results were 12case (76%) in arthroscopic repair and 7 cases (88%) in open cases. Conclusions Both arthroscopic or open Bankart could get good results in the treatment of anterior instability of shoulder. In arthroscopic repair, perioperative morbidity was lower than open repair, but it needs careful rehabilitation program to prevent redislocation and to return to sports activity.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.3
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• pp.149-155
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• 2006

This paper presents a torsional micromirror detached from PZT actuators (TMD), whose rotational motion is achieved by push bars in the PZT actuators detached from the micromirror. The push bar mechanism is intended to reduce the bending, tensile and torsional constraints generated by the conventional bending bar mechanism, where the torsional micromirror is attached to the PZT actuators (TMA). We have designed, fabricated and tested prototypes of TMDs for single-axis and dual-axis rotation, respectively. The single-axis TMD generates the static rotational angle of $6.1^{\circ}$ at 16 VDC, which is 6 times larger than that of single-axis TMA, $0.9^{\circ}$. However, the rotational response curve of TMD shows hysteresis due to the static friction between the cover and the push bar in the PZT actuator. We have shown that 63.2% of the hysteresis is due to the static friction caused by the initial contact force of the PZT actuaor. Without the initial contact force, the rotational response curve of TMD shows linear voltage-angle characteristics. The dual-axis TMD generates the static rotational angles of $5.5^{\circ}$ and $4.7^{\circ}$ in x-axis and y-axis, respectively at 16 VDC. The measured resonant frequencies of dual-axis TMD are $2.1\pm0.1$ kHz in x-axis and $1.7\pm0.1$ kHz in y-axis. The dual-axis TMD shows stable operation without severe wear for 21.6 million cycles driven by 16 Vp-p sinusoidal wave signal at room temperature.

• Journal of Korean Foot and Ankle Society
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• v.17 no.1
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• pp.28-33
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• 2013

Purpose: In previous study, the frequency of osteoarthritis and discomfort were high in ankle fracture-dislocation but detail results about ankle fracture-dislocation has rarely been investigated. In this study, we retrospectively analyze the outcome of the operative treatment of ankle fracture with dislocation for over-2 years follow up. Materials and Methods: There were 47 cases of ankle fracture-dislocation in our hospital from March 2007 to May 2010. We investigated 20 patients who underwent operation and were possible for over-2 years follow up. The result was estimated with the direction of dislocation, fracture type, the time of bone union and post-traumatic osteoarthritis with plain radiologic images. In clinical assessment, we statistically evaluated the function and pain through AOFAS score and Olerud & Molander scoring system. Results: By Lauge-Hansen classification, there were 13 cases(65%) of pronation-external rotation and 6 cases(30%) of supination-external rotation, 1 case(5%) of supination-adduction. AOFAS score was 85.5, and Olerud & Molander score was "excellent" in 8 cases, "good" in 5 cases, "fair" in 3 cases and "poor" in 4 cases. Postoperative complications in 4 cases revealed post-traumatic arthritis. All kinds of lateral dislocation of ankle fracture was 15 cases and the most common. Of these, all 3 cases, anterolateral dislocation showed post-traumatic osteoarthritis. Conclusion: In ankle fracture-dislocation, post-traumatic osteoarthritis occurred in 4 of 20 patient(20%). Especially, the possibility of post-traumatic osteoarthritis was more in cases of anterolateral or lateral dislocation. So, it must be needed that deliberate examination, for example, preoperative MRI and sufficient explanation to patient. Also, we have to follow up the patients carefully.

• Archives of Plastic Surgery
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• v.32 no.1
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• pp.93-99
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• 2005

In spite of proper maneuver of total knee replacement arthroplasty, some patients suffer from skin necrosis just above the implant. From Mar. 2000 to Jan. 2004, the authors performed reconstruction of knee skin defects after total knee replacement athroplasty. Total 6 cases of flap surgery were performed and patients ranged between 43-years-old to 82-years-old. Rectus femoris perforator based reversed adipofascial flaps were used in 2 cases, medial gastrocnemius muscular island flaps were used in 2 cases and sural artery based on adipofascial rotation flap was used in 1 case. One patient with extended necrosis underwent reconstruction with dual flaps of sural artery based adipofascial rotation flap and medial gastrocnemius muscular island flap. There were no distinctive complication needing additional procedure in all cases during the long term follow up. Reconstruction of necrosis following total knee replacement arthroplasty had several characteristics different from simple knee defect. The patients might have the history of long term steroid usages, excessive skin tension due to implants, underlying disease such as diabetes, rheumatoid disease, and etc. In addition, the early ambulation is mandatory in these patients of total knee replacement arthroplasty. With regards to these special considerations, a single stage and reliable operation must be needed. The authors introduce various reconstruction methods and algorithm that may aid easy decision making.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.6
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• pp.595-602
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• 2016

An automotive wheel bearing is important part that translates rotating motion and bears vehicle weight. Recently, in accordance with the demands for $CO_2$ emission reduction and fuel economy regulation, the requirements for the weight reduction and miniaturization of vehicles has increased. Therefore, life evaluation technology of the bearings has increased in necessity. Since the bearing life is affected by many parameters such as bearing geometry, bearing specifications, and vehicle specifications, it is difficult to predict. In this paper, the bearing life was tested by varying the applied load and rotation speed and comparing them with the basic rating life and modified rating life that were suggested in ISO standards. From the results, it was found that there was a difference between the test life and theoretical life and modified rating life than basic rating life was to be relatively well predicted by test life.