• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.3880-3899
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• 2019

Distributive desynchronization algorithms based on pulse-coupled oscillator (PCO) models have been proposed for achieving collision-free wireless transmissions. These algorithms do not depend on a global clock or infrastructure overheads. Moreover, they gradually converge to fair time-division multiple access (TDMA) scheduling by broadcasting a periodic pulse signal (called a 'firing') and adjusting the next firing time based on firings from other nodes. The time required to achieve constant spacing between phase neighbors is estimated in a closed form or via stochastic modeling. However, because these algorithms cannot guarantee the completion of desynchronization in a short and bounded timeframe, they are not practical. Motivated by the limitations of these methods, we propose a practical solution called PD-DESYNC that provides a short and deterministic convergence time using a flag firing to indicate the beginning of a cycle. We demonstrate that the proposed method guarantees the completion of desynchronization within three cycles, regardless of the number of nodes. Through extensive simulations and experiments, we confirm that PD-DESYNC not only outperforms other algorithms in terms of convergence time but also is a practical solution.

• 대한두개안면성형외과학회지
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• 제22권4호
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• pp.193-198
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• 2021

Background: Nasal bone fractures are frequently encountered in clinical practice. Although fracture reduction is simple and correction requires a short operative time, low patient satisfaction and relatively high complication rates remain issues for many surgeons. These challenges may result from inaccuracies in fracture recognition and assessment or inappropriate surgical planning. Findings from immediate postoperative computed tomography (CT) scans and those performed at 4 to 6 weeks postoperatively were compared to evaluate the accuracy and outcomes of nasal fracture reduction. Methods: This retrospective study included patients diagnosed with nasal bone fractures at our department who underwent closed reduction surgery. Patients who did not undergo additional CT scans were excluded from the study. Clinical examinations, patient records, and radiographic images were evaluated in 20 patients with nasal bone fractures. Results: CT findings from immediately after surgery and a 1month follow-up were compared in 20 patients. Satisfactory nasal projection and aesthetically acceptable results were observed in patients with accurate correction or mild overcorrection, while undercorrection was associated with unfavorable results. Conclusion: Closed reduction surgery for correcting nasal bone fractures usually provides acceptable outcomes with relatively few complications. If available, immediate postoperative CT scans are recommended to guide surgeons in the choice of whether to perform secondary adjustments if the initial results are unsatisfactory. Based on photogrammetric data, nasal bone reduction with accurate correction or mild overcorrection achieved acceptable and stable outcomes at 1 month postoperatively. Therefore, when upward dislocation is observed on postoperative CT, one can simply observe without a subsequent intervention.

• Journal of Chest Surgery
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• 제39권2호
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• pp.117-126
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• 2006

배경: 혈${\cdot}$기흉과 관련하여 우리나라에서 제기된 의료과오 소송들의 양상과 그 결과들을 살펴봄으로써 의사들이 혈${\cdot}$기흉 환자 처치에 있어서 의학적 적응증과 정확한 술기방법 외에 의료법학적으로 고려하여야 하는 부분을 밝혀 발생 가능한 소송에 대처하려 한다. 대상 및 방법: 혈${\cdot}$기흉과 관련된 의료소송 중 재판종결 후 판결문이 공개된 판례들을 대상으로 Lawnb site (www.lawnb.com)와 법원에서 제공하는 법고을 시디롬을 검색하여 혈${\cdot}$기흉 발생 원인, 환자 나이, 기저질환, 소송결과 및 배상금 등을 조사하여 검토하였다. 결과: 대법원 판례 3건, 고등법원 판례가 1건, 지방법원 판례가 3건으로 총 7건의 판결문이 검색되었고 소송결과 3건은 원고가 일부 승소하였고, 4건의 경우는 원고의 청구를 기각하여 파기 환송하였다. 사망 사고의 경우 소송의 원인이 된 사인 중 가장 흔한 원인은 긴장성 기흉이었다. 결론: 혈${\cdot}$기흉과 관련된 소송의 빈도가 높은 것은 아니지만, 환자의 사망 또는 발생한 후유증으로 인해 발생한 손해에 대한 배상액이 상당하다. 소송의 발생은 소아 환자에게 발생한 혈${\cdot}$기흉의 경우가 더 흔하다. 의인성 기흉의 경우 시술 후 방사선 촬영여부가 환자의 예후 및 소송에 있어서 의사를 방어하는 증거로 제시될 수 있고, 충분한 설명에 근거한 동의 역시 중요하다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권4호
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• pp.169-172
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• 2014

Objectives: The purpose of this retrospective study was to compare the amount of postoperative drainage via closed suction drainage system after intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO). Materials and Methods: We planned a retrospective cohort study of 40 patients selected from a larger group who underwent orthognathic surgery from 2007 to 2013. Mean age (range) was 23.95 (16 to 35) years. Patients who underwent bilateral IVRO or SSRO were categorized into group I or group II, respectively, and each group consisted of 20 patients. Closed suction drainage system was inserted in mandibular osteotomy sites to decrease swelling and dead space, and records of drainage amount were collected. The data were compared and analyzed with independent t-test. Results: The closed suction drainage system was removed at 32 hours postoperatively, and the amount of drainage was recorded every 8 hours. In group I, the mean amount of drainage was 79.42 mL in total, with 31.20 mL, 19.90 mL, 13.90 mL, 9.47 mL, and 4.95 mL measured at 0, 8, 16, 24, and 32 hours postoperatively, respectively. In group II, the mean total amount of drainage was 90.11 mL, with 30.25 mL, 25.75 mL, 19.70 mL, 8.50 mL, and 5.91 mL measured at 0, 8, 16, 24, and 32 hours postoperatively, respectively. Total amount of drainage from group I was less than group II, but there was no statistically significant difference between the two groups (P=0.338). There was a significant difference in drainage between group I and group II only at 16 hours postoperatively (P=0.029). Conclusion: IVRO and SSRO have different osteotomy design and different extent of medullary exposure; however, our results reveal that there is no remarkable difference in postoperative drainage of blood and exudate.

• Archives of Plastic Surgery
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• 제44권1호
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• pp.42-47
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• 2017

Background Skin erosion is a dire complication of implantable cardiac pacemakers and defibrillators. Classical treatments involve removal of the entire generator and lead systems, however, these may result in fatal complications. In this study, we present our experience with a simplified salvage technique for exposed implantable cardiac electronic devices (ICEDs) without removing the implanted device, in an attempt to reduce the risks and complication rates associated with this condition. Methods The records of 10 patients who experienced direct ICED exposure between January 2012 and December 2015 were retrospectively reviewed. The following surgical procedure was performed in all patients: removal of skin erosion and capsule, creation of a new pocket at least 1.0-1.5 cm inferior to its original position, migration of the ICED to the new pocket, and insertion of closed-suction drainage. Patients with gross local sepsis or septicemia were excluded from this study. Results Seven patients had cardiac pacemakers and the other 3 had implantable cardiac defibrillators. The time from primary ICED placement to exposure ranged from 0.3 to 151 months (mean, 29 months. Postoperative follow-up in this series ranged from 8 to 31 months (mean follow-up, 22 months). Among the 10 patients, none presented with any signs of overt infection or cutaneous lesions, except 1 patient with hematoma on postoperative day 5. The hematoma was successfully treated by surgical removal and repositioning of the closed-suction drainage. Conclusions Based on our experience, salvage of exposed ICEDs is possible without removing the device in selected patients.

• Journal of Chest Surgery
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• 제21권5호
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• pp.871-876
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• 1988

Spontaneous pneumothorax is a common surgical problem and occurs most frequently in male patients under 40 years of age. The records of 336 cases in 269 patients, diagnosed and treated as spontaneous pneumothorax during the period of 1981, Jan.- 1987, Dec., at the department of thoracic and cardiovascular surgery, college of medicine, Hallym university, were reviewed retrospectively. The results were as follows; 1. Spontaneous pneumothorax was commonly found between the age of 20-40[55%]. 2. Sexual ratio of male to female was 4.4:1. 3. The most common symptoms were dyspnea and chest discomfort or chest pain. 4. Pulmonary tuberculosis was the most common cause of the disease[30.8%]. 5. Recurrent rate after closed thoracotomy drainage was 28.2%, and not recurred after operation. 6. Bullae or blebs were found most commonly at the apical segment of both upper lobes.

• 대한치과교정학회지
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• 제37권4호
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• pp.272-282
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• 2007

본 연구의 목적은 구순이 이완되도록 개구한 상태(relaxed lip position)에서 촬영한 측모 두부방사선사진과 일반적으로 채득하는 중심교합위에서 입술을 다문 상태(closed lip position)의 측모 두부방사선 사진에서 비순각의 변화 양상을 비교하여 안모 분석 시 relaxed lip position의 중요성을 검토하는 것이다. 전치부 반대교합을 보이는 골격성 III급 부정교합 성인환자(평균 23.3세) 60명(남자 35명, 여자 25명)을 연구대상으로 선정하였다. 구순이 이완되도록 개구한 상태에서와 중심교합 상태에서의 비순각 차이를 비교한 결과 유의성 있는 차이가 있었으며, 비순각의 변화량 사이의 유사성을 기준으로 좀 더 객관적으로 분류하여 분석하고자 군집분석을 통해 제1군(27명, 45%, 구순 이완시 비순각이 감소하는 군), 제2군(30명, 50%, 구순 이완 시 비순각이 증가하는 군), 제3군(3명, 5%, 구순 이완 시 비순각이 예외적으로 크게 증가하는 군)으로 분류하였다. 제1군에서는 상순이 전체적으로 후방 이동되며 비순각은 변화가 없거나 오히려 감소하였으며, 제2군에서는 상순이 후하방 회전되며 비순각이 증가하였다. 제3군에서는 상순이 하순과 하악전치에 의해 상방으로 압박되었다가(compression)이완되며 비순각이 크게 증가하였다. 이상의 연구 결과에서 골격성 III급 부정교합자에서 구순이 이완된 상태에 대해 중심 교합 시의 비순각의 변화가 다양한 것을 알 수 있었다. 따라서 정확한 안모분석과 수술-교정 치료 후의 연조직 심미성의 예측을 위해 기록 채득과 분석 시 이완된 구순 위치에 대한 고려가 필요하며 이러한 자세로 진단용 방사선 사진을 촬영하는 것이 필요하다고 생각되었다.

• Advances in pediatric surgery
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• 제15권1호
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• pp.18-26
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• 2009

The survival of Very Low Birth Weight (VLBW) infants has been improved with the advancement of neonatal intensive care. However, the incidence of accompanying gastrointestinal complications such as necrotizing enterocolitis has also been increasing. In intestinal perforation of the newborn, enterostomy with or without intestinal resection is a common practice, but there is no clear indication when to close the enterostomy. To determine the proper timing of enterostomy closure, the medical records of 12 VLBW infants who underwent enterostomy due to intestinal perforation between Jan. 2004 and Jul. 2007 were reviewed retrospectively. Enterostomy was closed when patients were weaned from ventilator, incubator-out and gaining adequate body weight. Pre-operative distal loop contrast radiographs were obtained to confirm the distal passage and complete removal of the contrast media within 24-hours. Until patients reached oral intake, all patients received central-alimentation. The mean gestational age of patients was $26^{+2}$ wks ($24^{+1}{\sim}33^{+0}$ wks) and the mean birth weight was 827 g (490~1450 g). The mean age and the mean body weight at the time of enterostomy formation were 15days (6~38 days) and 888 g (590~1870 g). The mean body weight gain was 18 g/day (14~25 g/day) with enterostomy. Enterostomy closure was performed on the average of 90days (30~123 days) after enterostomy formation. The mean age and the mean body weight were 105 days (43~136 days) and 2487 g (2290~2970 g) at the time of enterostomy closure. The mean body weight gain was 22 g/day after enterostomy closure. Major complications were not observed. In conclusion, the growth in VLBW infants having enterostomy was possible while supporting nutrition with central-alimentation and the enterostomy can be closed safely when the patient's body weights is more than 2.3 kg.

• 국제초고층학회논문집
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• 제3권4호
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• pp.255-271
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• 2014

A method of smart system identification of super high-rise buildings is proposed in which super high-rise buildings are modeled by a shear-bending system. The method is aimed at finding the story shear and bending stiffnesses of a specific story only from the horizontal floor accelerations. The proposed method uses a set of closed-form expressions for the story shear and bending stiffnesses in terms of the limited floor accelerations and utilizes a reduced shear-bending system with the same number of elements as the observation points. A difficulty of prediction of an unstable specific function in a low frequency range can be overcome by introducing an ARX model and discussing its relation with the Taylor series expansion coefficients of a transfer function. It is demonstrated that the shear-bending system can simulate the vibration records with a reasonable accuracy. It is also shown that the vibration records at two super high-rise buildings during the 2011 Tohoku (Japan) earthquake can be simulated with the proposed method including a technique of inserting degrees of freedom between the vibration recording points. Finally it is discussed further that the time-varying identification of fundamental natural period and stiffnesses can be conducted by setting an appropriate duration of evaluation in the batch least-squares method.

• Archives of Plastic Surgery
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• 제36권2호
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• pp.242-246
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• 2009

Purpose: The majority of nasal bone fractures have been managed by routine procedure of closed reduction and intranasal packing. However, nasal packing can cause nasal injury, hypoxia and patient's discomfort. And, synechiae formation is a frequently occurred after the nasal surgery. Various methods are used to reduce the incidence of synechiae formation. The purpose of this study was to compare routine procedure and nasal packing with reverse "U" shaped silicone sheet with respect to postoperative nasal synechiae formation and final outcome. Methods: We analyzed the medical records of 100 patients with nasal bone fracture who were operated by closed reduction in the last one year. The silicone sheet was designed in reverse "U" fan - shape and inserted between the middle turbinate and the septal wall. Nasal packing was removed at two days after the operation, and silicone sheet was removed at 10 to 14 days. Results: Synechiae in the middle meatus developed in 2 of 75 patients. Although synechiae between the middle meatus and nasal septum occurred in patients, the patients did not complaint of any olfactory disturbance and nasal obstruction. Conclusion: The reverse "U" fan - shape silicone sheet caused less pain for patients and no significant differences in outcome were found. The results of this study suggest that insertion of silicone sheet between the middle meatus and septum can be a useful method in the prevention of intranasal synechiae formation. The reverse "U" silicone sheet is a good alternative for routine packing methods.