• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권5호
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• pp.435-441
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• 2001

Orthognathic surgery for the correction of dentofacial deformities is a common elective procedure. That has proven over the years to be a safe operation with minimal long-term morbidity. But, there are many surgical complication including mal-union of the bone, TMJ problem, excessive bleeding, and permanent damage of inferior alveolar nerve. Among them excessive bleeding which focus is not clear is one of the serious complication because that is fatal and so a transfusion is performing for the prevention and management of that. Until the end of the 1980's, homologous blood transfusions were routinely necessary because of the large amounts of blood lost during surgery. Recently several blood-saving measures can be undertaken for orthognathic surgery patients before, during, and after the operation. We made a comparative study of an amount of blood loss, hematologic change and transfusion requirements based on a series of 40 consecutive patients undergoing single-jaw and double-jaw surgery. The purpose of this investigation was to make a comparative analysis of an amount of blood loss, post-operative hematologic change and duration of the procedure under induced hypotensive anesthesia in healthy orthognathic patients.

• 한국통신학회논문지
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• 제33권10C호
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• pp.805-812
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• 2008

H.264 기술은 차세대 동영상 코덱 표준의 핵심으로 간주되고 있다. 유럽을 포함하여 많은 나라에서는 HD 방송을 위한 동영상 코덱 표준으로 H.264 기술을 사실상 지정해 놓고 있는 실정이다. 하지만 복잡한 알고리즘 사용으로 인해 HD급 영상의 경우에는 아직도 데스크탑 컴퓨터에서조차 실시간 복호화가 어려운 상황이다. 본 논문에서는 실시간으로 동작이 보장되는 H.264 소프트웨어 동영상 복호기를 구현하기 위해서 복호화 과정의 일부를 제한하고, 이에 따른 화질열화가 최소가 되는 알고리즘들을 적응적으로 선택하는 H.264 복호기를 제안한다. 제안하는 H.264 복호기는 PC 환경에서 모의실험을 통해 성능을 비교 및 검증하였다. 그 결과 실시간 복호화가 어려운 환경에서 제안하는 복호기를 사용하였을 경우 대부분 최소한의 화질 열화와 함께 실시간 복호화를 만족하는 결과를 보였다.

• 대한두개안면성형외과학회지
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• 제15권2호
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• pp.82-88
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• 2014

Background: The chin shape and position is important in determining the general shape of the face, and augmentation genioplasty is performed alone or in combination with other aesthetic procedures. However, augmentation genioplasty using osteotomy is an invasive and complex procedure with the potential to damage mentalis muscle and mental nerve, to affect chin growth, and prolonged recovery. Our aim was to present our experience with a modified augmentation genioplasty procedure for hypoplastic chins using a Gore-Tex implant. Methods: Two vertical slit incisions were made at the canine level to create a supra-periosteal pocket between the incisions, preserving the periosteum and mentalis muscle. Minimal sub-periosteal dissection was performed lateral to the incisions along the mandibular border. The both wings of implant were inserted under the periosteum to achieve a stable dual plane implantation. Results: In total, 47 patients underwent dual plane chin augmentation using a Gore- Tex implant between January 2008 and May 2013. The mean age at operation was 25.77 years (range, 15-55 years). There were 3 cases of infection; one patient was treated with antibiotics, the others underwent implant removal. Additionally, two patients complained of postoperative parasthesia that spontaneously improved without any additional treatment. Most patients were satisfied with the postoperative outcomes, and no chin growth problems were observed among the younger patients. Conclusion: Dual plane Gore-Tex chin augmentation is a minimally-invasive operation that is simple and safe. All implants yielded satisfactory results with no significant complications such as mental nerve injury, lower lip incompetence, or chin growth limitation.

• Annals of Clinical Neurophysiology
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• 제16권1호
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• pp.21-26
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• 2014

Background: Electrophysiological study has been known as a useful method to evaluate the therapeutic effect of operation in idiopathic carpal tunnel syndrome (CTS). The purpose of this study was to evaluate the clinical and electrophysiological changes after carpal tunnel release (CTR) compared to the preoperative results. Methods: We analyzed the changes of nerve conduction study (NCS) before and after minimal open carpal tunnel release in 18 patients (25 hands) with CTS. Follow-up study was performed over 6 months after operation. Results: Clinical improvement was seen in all cases after CTR. In contrast, electrophysiological improvement was various depending on the parameters; the mean median sensory latency and nerve conduction velocity (NCV) improved significantly (p = 0.001). The mean median motor latency also improved, but NCV and compound muscle action potential (CMAP) amplitude did not change. The extent of improvement was evident in moderate CTS, but not in severe CTS. Conclusions: In this preliminary study, all subjects who underwent CTR achieved a clinical relief along with a significant improvement of electrophysiological parameters such as median sensory latency, sensory NCV and median distal motor latency. After CTR, a number of cases with mild to moderate CTS showed a prominent improvement of clinical and electrophysiological parameters, while fewer improvements were seen in severe CTS, although it did not reach the statistical significance.

• 대한두개안면성형외과학회지
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• 제19권3호
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• pp.235-239
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• 2018

Intraoperative expansion has been used to cover small to large defects without disadvantages of the conventional tissue expanders. Various materials, for example, expanders and Foley catheters are being used. We introduce a new, convenient and economical device immediately available in the operating room, according to the defect size for intraoperative expansion, with latex gloves or balloons. The retrospective study was done with 20 patients who presented with skin and soft tissue defects. During the operation, expansion was done with latex gloves or balloons inflated with saline through an intravenous line and a three-way stopcock. After the inflation, the glove was removed and skin was covered with expanded tissue. A careful decision was made regarding the inflation volume and placement of the expander according to the defect size. There were no postoperative complications. The skin contracture and tension was minimal with a texture similar to the adjacent tissue. The new intraoperative expansion devices with latex gloves and balloons were cheap and made easily right in the operation room. The reconstruction of small to large sized skin defects can be done successfully, functionally and aesthetically without using expensive commercial materials.

• 한국철도학회논문집
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• 제19권4호
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• pp.489-497
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• 2016

레일체결장치는 레일을 침목 등에 결속시켜 정해진 궤간의 유지와 열차 하중을 하부의 침목 및 도상 등에 전달하는 역할을 수행하는 주요 궤도 구성품이다. 본 논문에서는 도시철도 운영환경에서 파상마모에 대한 레일체결장치 클립의 진동 특성 분석을 위해서 조립상태에서 레일체결장치 클립의 모달테스트를 수행하여 고유진동수를 측정하였으며, 이를 파상마모에 의한 통과주파수와의 비교를 통해 공진 영향을 검토하였다. 또한 열차 주행시 파상마모에 따른 레일 및 레일체결장치 클립의 가속도와 레일체결장치 클립의 변형률을 계측하였다. 분석결과 레일 및 레일체결장치 클립의 가속도는 파상마모와 매우 밀접한 관계를 가지고 있으나, 레일체결장치 클립의 변형률과의 관계는 미비한 것으로 나타났다.

• The Journal of the Acoustical Society of Korea
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• 제18권3E호
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• pp.37-43
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• 1999

In this paper, we present a new technique for the optimal local decomposition of convex structuring elements on a hexagonal grid, which are used as templates for morphological image processing. Each basis structuring element in a local decomposition is a local convex structuring element, which can be contained in hexagonal window centered at the origin. Generally, local decomposition of a structuring element results in great savings in the processing time for computing morphological operations. First, we define a convex structuring element on a hexagonal grid and formulate the necessary and sufficient conditions to decompose a convex structuring element into the set of basis convex structuring elements. Further, a cost function was defined to represent the amount of computation or execution time required for performing dilations on different computing environments and by different implementation methods. Then the decomposition condition and the cost function are applied to find the optimal local decomposition of convex structuring elements, which guarantees the minimal amount of computation for morphological operation. Simulation shows that optimal local decomposition results in great reduction in the amount of computation for morphological operations. Our technique is general and flexible since different cost functions could be used to achieve optimal local decomposition for different computing environments and implementation methods.

• 디지털콘텐츠학회 논문지
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• 제13권1호
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• pp.75-81
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• 2012

SSD (Solid-State Drives)는 고성능, 저전력, 내구성과 경량 등의 특징을 가지고 있어 빠른 속도로 하드 디스크를 대체하고 있다. SSD는 하드디스크와 같은 블록 저장장치로 에뮬레이트하는 계층인 FTL(Flash Translation Layer) 을 가지고 있다. 가비지 컬렉션(Garbage Collection)은 FTL의 주요한 기능으로서 SSD의 수명과 성능에 큰 영향을 끼친다. 그러나 아직까지 새로운 알고리즘을 검증하기 위한 사실상의 표준이 없는 상황이다. 본 논문에서는 이 문제를 해결하기 위해 트레이스 기반의 오프라인 최적 알고리즘을 제안한다. 제안한 알고리즘은 언제나 최소 횟수의 지우기 연산을 보장한다. 추가적으로 본 논문에서는 TPC 트레이스를 사용하여 제안한 알고리즘의 유효성에 대해 검증하였다.

• ETRI Journal
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• 제42권4호
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• pp.480-490
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• 2020

More than 42 000 fires occur nationwide and cause over 2500 casualties every year. There is a lack of specialized equipment, and rescue operations are conducted with a minimal number of apparatuses. Through-the-wall radars (TTWRs) can improve the rescue efficiency, particularly under limited visibility due to smoke, walls, and collapsed debris. To overcome detection challenges and maintain a small-form factor, a TTWR system-on-chip (SoC) and its architecture have been proposed. Additive reception based on coherent clocks and reconfigurability can fulfill the TTWR demands. A clock-based single-chip infrared radar transceiver with embedded control logic is implemented using a 130-nm complementary metal oxide semiconductor. Clock signals drive the radar operation. Signal-to-noise ratio enhancements are achieved using the repetitive coherent clock schemes. The hand-held prototype radar that uses the TTWR SoC operates in real time, allowing seamless data capture, processing, and display of the target information. The prototype is tested under various pseudo-disaster conditions. The test standards and methods, developed along with the system, are also presented.

• 한국안전학회지
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• 제35권3호
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• pp.86-95
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• 2020

This paper describes the work and the results of the final Probabilistic Safety Assessment (PSA) for the Jordan Research and Training Reactor (JRTR). This final PSA was undertaken to assess the level of safety for the design of a research reactor and to evaluate whether it is probabilistically safe to operate and reliable to use. The scope of the PSA described here is a Level 1 PSA, which addresses the risks associated with core damage. After reviewing the documents and its conceptual design, nine typical initiating events were selected regarding internal events during the normal operation of the reactor. AIMS-PSA (Version 1.2c) was used for the accident quantification, and FTREX was used as the quantification engine. 1.0E-15/yr of the cutoff value was used to deliminate the non-effective Minimal Cut Sets (MCSs) when quantifying the JRTR PSA model. As a result, the final result indicates a point estimate of 2.02E-07/yr for the overall Core Damage Frequency (CDF) attributable to internal initiating events in the core damage state for the JRTR. A Loss of Primary Cooling System Flow (LOPCS) is the dominant contributor to the total CDF by a single initiating event (9.96E-08/yr), and provides 49.4% of the CDF. General Transients (GTRNs) are the second largest contributor, and provide 32.9% (6.65E-08/yr) of the CDF.