• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.308-311
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• 2021

This paper describes the development of a functional game for preventing dementia for the elderly based on virtual reality. The game was developed using the Unity 3D engine to create a fishing spot, a virtual reality space. In consideration of the fact that the object of the game is an elderly person relatively unfamiliar with the virtual reality, the number of operation buttons is minimized and the sense of resistance and fatigue are reduced by an intuitive game configuration. In addition, the game was designed to give people a sense of accomplishment with a score system after the game, and to encourage them to participate in the game Overall, the developed game consists of main, interface, stage, score, TTS, tutorials, and ending credit. Each category stage is divided into three stages and realized in one integrated environment, and VRHMD can be used to games that enhance memory, attention, and judgment.

• Journal of Chest Surgery
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• v.57 no.2
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• pp.169-177
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• 2024

Background: Pericardial effusion (PE) is a serious condition in cancer patients, primarily arising from malignant dissemination. Pericardial window formation is a surgical intervention for refractory PE. However, the long-term outcomes and factors associated with postoperative survival remain unclear. Methods: We retrospectively analyzed data from 166 oncology patients who underwent pericardial window formation at Samsung Medical Center between 2011 and 2023. We analyzed survival and PE recurrence regarding surgical approach, cancer type, and cytopathological findings. To identify factors associated with survival, we utilized Cox proportional-hazards regression. Results: All patients had tumors documented in accordance with the American Joint Committee on Cancer staging manual, including lung (61.4%), breast (9.6%), gastrointestinal (9.0%), hematologic (3.6%), and other cancers (16.4%). Surgical approaches included mini-thoracotomy (67.5%) and thoracoscopy (32.5%). Postsurgical cytopathology confirmed malignancy in 94 cases (56.6%). Over a median follow-up duration of 50.0 months, 142 deaths and 16 PE recurrences occurred. The 1-year overall and PE recurrence-free survival rates were 31.4% and 28.6%, respectively. One-year survival rates were significantly higher for thoracoscopy recipients (43.7% vs. 25.6%, p=0.031) and patients with negative cytopathology results (45.1% vs. 20.6%, p<0.001). No significant survival difference was observed between lung cancer and other types (p=0.129). Multivariate analysis identified New York Heart Association class, cancer stage, and cytopathology as independent prognostic factors. Conclusion: This series is the largest to date concerning window formation among cancer patients with PE. Patients' long-term survival after surgery was generally unfavorable. However, cases with negative cytopathology or earlier tumor stage demonstrated comparatively high survival rates.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1126-1135
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• 2000

Objectives : The goal of surgical management of cerebral arteriovenous malformation(AVM) is elimination of the lesion without development of new neurological deficits. To improve the management results of cerebral AVMs in the future, this article discusses about surgical complications of the AVM and their management. Material and Methods : During the past 18 years, 116 patients with cerebral AVMs were managed by surgery. Among these cases, 7 cases died, 7 cases developed new neurological deficits, 11 cases residual AVM and 5 cases intracerebral hematoma(ICH) after surgery. The author analyzes the causes of those complications and investigates the methods to minimized those complications based on the review of the literatures. Results : One stage removal of AVM and ICH in the poor neurological state were performed in 5 of 7 death cases. Subtotal removal of ICH followed by delayed AVM surgery after recovery is regard as one method to improve the outcome of patient with large ICH. Postoperative new neurological deficits developed owing to normal perfusion pressure breakthrough(NPPB) in 3, judgement error in 2, preoperative embolization in 1 and cortical injury in 1 case(s). Proper management of NPPB, accurate anatomical knowledge and physiological monitoring during operation, and well trained skill for embolization are regard as methods to minimize those complications. Residual AVMs after surgery were noticed in 11 cases, in which unintended 6 cases due to inaccurate dissection of peripheral margin of AVM, and intended 3 cases due to massive brain swelling during operation, 1 cases due to diffuse type and 1 case due to multiple type of AVM. Accurate dissection of peripheral margin of AVM and mild hypotension during operation may help to avoid this complication. Postoperative hemorrhage occurred in 3 cases due to rupture of the residual AVM and in 2 cases due to oozing from the AVM bed. Complete resection of AVM, complete control of bleeding points at AVM bed and mild hypotension during early postoperative period are the methods to avoid this complication. Conclusion : A precise but flexible therapeutic strategy and refined skill for endovascular, radiosurgical and microsurgical techniques are required to successful treatment of cerebral AVM. Adequate timing of AVM resection, accurate anatomical knowledge, proper management of NPPB and accurate dissection of peripheral margin of AVM are the key points for avoiding complications of the AVM surgery.

• Journal of the Korean Arthroscopy Society
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• v.14 no.2
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• pp.114-119
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• 2010

Purpose: The purpose of this study was to assess the result of arthroscopic treatment in septic knee arthritis and evaluate the prognostic factor over 50 years old. Materials and Methods: Fifty-two patients were treated by arthroscope for septic knee arthritis from January, 2002 to August, 2005. The mean follow-up period was 27.5months. We assessed Lysholm score as functional result, CRP normalized period as laboratory result, and knee range of motion as clinical result. We evaluated patient's age, underlying disease, causative organism, previous knee status (Kellgren stage), clinical status of septic arthritis (G$\ddot{a}$chter stage) and history of intra-articular injection as prognostic factor. Results: Mean Lysholm score was improved from 40.7 to 67.1. And the mean CRP normalized period was 38.7days. At last follow-up, almost patient (92%) were recovered to prior knee full range of motion and 45 patient (74%) were completely cured by one stage operation. The microorganism isolated were MSSA (n=13), MSSE (n=3), MRSA/MRSE (n=4),no microorganism (n=27) and others (n=5). In Lysholm score, young age (42.8(preop.)$\rightarrow$83.5(postop.)), Kellgren stage 0 ($45.5{\rightarrow}84.2$), G$\ddot{a}$chter stage I ($39.3{\rightarrow}73.1$) and no microorganism (442.1{\rightarrow}72.6$) were more increased than old age (439.3{\rightarrow}61.7$), Kellgren IV ($28.3{\rightarrow}43.7$), G$\ddot{a}$chter stage IV ($40.2{\rightarrow}67.1$) and MRSA/MRSE ($40{\rightarrow}58.75$). In case of old age (42.3days), G$\ddot{a}$chter stage IV (55.5), Kellgren stage IV(43.7), DM patient (42.1) and intra-articular injection history (52.1), the CRP titer normalized period was longer than mean period. MRSA/MRSE(n=3,75%) were not normalized in CRP titer at last follow-up. Conclusion: Arthroscopic treatment of septic knee would be an effective and satisfactory procedure. Age, previous knee status (Kellgren stage), underlying disease (DM), intra-articular injection history, microorganism and Ga¨chter stage effect end result outcome.

• Archives of Plastic Surgery
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• v.50 no.6
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• pp.557-562
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• 2023

Augmentation mammoplasty is one of the most popular cosmetic surgeries, but there is a high reoperation rate (29.7%) commonly due to capsular contracture, implant malpositioning, infection, and unsatisfactory size. Although infection only accounts for 2% of cases, its management is very challenging, especially with nontuberculous mycobacteria (NTM) infection. Breast prosthetic NTM infection is a rare but is a disastrous condition with an incidence of approximately 0.013%. Immediate salvage reimplantation is usually not suggested, and most studies recommend a gap of 3 to 6 months after combination antibiotics therapy before reimplantation. However, delayed reimplantation often leads to great psychological stress and struggle between the doctor and patient. We present the case report of successful reimplantation in treating prosthetic NTM infections in a 28-year-old female. We discuss a novel technique "transaxillary capsulorrhaphy" to correct the bottoming-out deformity. One year after the combination of antibiotics and surgery, the follow-up computed tomography scan showed complete remission of NTM without recurrence. We discuss the surgical technique in detail. The 1-year follow-up assessment (photos and dynamic video) revealed good cosmesis and reliable correction using the new technique. This report is the first formal description and discussion of one-stage reimplantation following NTM infections. Transaxillary capsulorrhaphy allows for a successful salvage operation when an implant is displaced. This approach provides highly favorable result in eastern women undergoing revision augmentation mammoplasty. This study reflects level of evidence V, considering opinions of respected authorities based on clinical experience, descriptive studies, or reports of expert committees.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.238-246
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• 2015

A stepping motor is widely used to operate the elevation and azimuth stage of the X-band antenna with 2-axis gimbal system for effective image data transmission from a satellite to a ground station. However, such stepping motor also generates an undesirable micro-vibration which is one of the main disturbance sources affecting image quality of the high-resolution observation satellite. In order to improve the image quality, the micro-vibration isolation of the X-band antenna system is essential. In this study, the low rotational stiffness isolator has been proposed to reduce the micro-vibration disturbance induced by elevation direction operation of the X-band antenna. In addition, its structural safety was confirmed by the structure analysis based on the derived torque budget. The effectiveness of the design was also verified through the micro-vibration measurement test.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.336-339
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• 1997

The surgical treatment of diseases of thoracic aorta has had much better success rate in recent years compaired to the past. Aortic aneurysms or dissections that extend along the entire thoracic aorta are usually approached in two or three stages. Recently we successfully perfofm d one-stage aortic replacement from the aortic root to the abdominal aorta in chronic DeBakey type I dissection. A 25 year-old man who had dyspnea on exertion (NYHA Fc II) and a Marfanoid feature was operated under the diagnosis of chronic type I dissection with severe aortic regurgitation. ' At operation, a huge ascending aorta with two intimal tearings was seen and the blood supply of intercostal arteries and right renal artery was done from the false lumen. Modified Bentall operation with total aortic replacement was done successfully, and the patient is being followed-up without major complications.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.102-106
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• 1999

We have designed and fabricated a four-bit shift register circuit using YBCO bicrystal junctions and experimentally tested its operations by a computer-controlled digital measurement set-up. Laser ablated YBCO thin films with clean surface were used in this work. The circuit consists of the shift register and two read SQUIDs placed next to each sides of the shift register. The SQUIDs were inductively coupled to the nearby shift register stages. A probe equipped with high speed coax lines were used in this experiment. The major obstacle in testing the circuit was the interference between the read SQUIDs and we solved the problem by finding the correct operation points of the SQUIDs from the simultaneously measured modulation curves. Loaded Data("1" or "0") were successfully shifted from a stage to the next one by a controlled current pulse injected to the bias lines located between the stages and the data shifts were correctly monitored by the read SQUIDs

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1727-1736
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• 2006

In a fuzzy control system to vocess fuzzy data in high-speed for intelligent systems, one of the important problems is the improvement of the execution speed in the fuzzy inference and defuzzification stages. Especially, it is more important to have high-speed operations in the consequent Pan and defuzzification stage. Therefore, in this paper, to improve the speedup of the fuzzy controllers for intelligent systems, we propose novel integer fuzzy operation method without mulitplications and divisions by only integer addition to convert real values in the fuzzy membership functions in the consequent part to integer grid pixels $(400{\times}30)$ without [0, 1] real operations. Also we apply the proposed system to the truck backer-upper control system. As a result, this system shows a real-time very high speed fuzzy control as compared as the conventional methods. This system will be applied to the real-time high-speed intelligent systems such as robot arm control.

• Archives of Craniofacial Surgery
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• v.13 no.2
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• pp.139-142
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• 2012

Purpose: To reconstruct the midface, local flaps such as nasolabial flaps have been frequently used. These local flaps, however, have the shortcomings of requiring a secondary operation or limitations in the movement of the flap. Thus, new methods have been developed. This paper reports a case wherein the basal cell carcinoma on the cheek was resected and the skin and soft tissue defect was successfully treated using a facial artery perforator flap. Methods: A 68-year-old female consulted the authors on the basal cell carcinoma that developed on her cheek. The mass was fully resected and revealed a $2.3{\times}2.3cm$ defective region. Using a Doppler ultrasonography, the facial artery path was traced, and using a loupe magnification, the facial artery perforator flap was elevated and the defective region was covered with the flap. Results: The flap developed early venous congestion, but it disappeared without any treatment. Six months after the surgery, the patient was satisfied with the postoperative result. Conclusion: The facial artery perforator flap has a thin pedicle. It offers a big arc of the rotation that allows free movement and one-stage operation. These strengths make the method useful for the reconstruction of the midface among other procedures.