• 한국지진공학회논문집
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• 제9권2호통권42호
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• pp.71-80
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• 2005

유체자유수면의 동적거동을 합리적으로 예측하기 위해서는 비선형 특성을 보이는 자유수면의 동역학적 경계조건을 고려해야할 뿐만 아니라 시간에 따라 변화하는 자유수면의 위치변화에 따른 운동학적 경계조건을 고려하여야 한다. 이러한 문제는 대상구조물이 3차원이 될 경우 더욱 복잡해지므로 3차원 비선형 유체자유수면의 해석은 이론해의 도출이 어려우며 수치해석 방법을 이용하는 것이 효과적이다. 본 연구에서는 수치해석 안정성이 높고 3차원 문제에서도 하나의 변수로 유체거동을 모사할 수 있는 arbitrary Lagrangian-Eulerian approach 를 경계요소에 적용하여 효율적이며 안정적인 유체 대변형 해석기법을 개발하였다. 개발된 기법은 향후 자유수면의 비선형 효과를 고려한 유체-구조물 상호작용 해석에 효과적으로 적용할 수 있을 것으로 판단된다.

• Journal of Korean Dental Science
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• 제3권2호
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• pp.12-19
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• 2010

Despite the latest advancement made in its techniques and devices/apparatuses and the resulting rising expectation in the field of dental surgery, apicoectomy performed in the molar teeth remains a technical challenge and lacks evidence substantiated by long-term follow-up studies. This study sought to investigate the treatment outcomes and post-operative success rate in the root-end resected molar teeth accompanied by a high level of surgical risks due to their close proximity to the mandibular canal and maxillary sinus. A total of 68 patients who received treatment at Livingwell Dental Hospital between 2004 and 2010 and underwent apical surgery in the maxillary or mandibular molar area were enrolled in this study. A total of 160 roots collected from 75 molar teeth were subjected to surgical endodontic treatment and subsequently evaluated clinically as well as radiographically. Based on the results of the study, the clinical success rate was found to be 78.8% in cases involving radiological healing. Likewise, 90.7% of the roots recorded a robust clinical survival rate, but with incomplete healing as shown by radiography. The results indicate that the apical procedure involving molar teeth is a prognosis-friendly method that promises positive outcomes and higher success rate based on long-term follow-up observations.

• 한국통신학회논문지
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• 제30권1A호
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• pp.91-103
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• 2005

주문형 비디오 시스템의 설계에 있어 가장 중요하게 고려되고 있는 것은 사용되는 채널의 수를 일정하게 유지하면서 자입자의 대기시간을 줄이는 방법이다. 이러한 연구의 한 시도로 근래에 실시간 주문형 비디오와 유사주문형 비디오의 장점을 결합하는 결합형 주문형 비디오에 대한 연구가 활발히 이루어지고 있다. 결합형 주문형 비디오에 대한 연구는 결국 어떻게 유니캐스트 채널을 사용하는 사용자들을 그룹화하여 멀티캐스트 채널을 사용하도록 할 것인가에 대한 연구이다. 본 논문에서는 동적인 채널을 이용하여 시청자의 대기시간을 기존의 방식에 비해 효율적으로 줄일 수 있는 결합형 주문형 비디오를 제안하겠다. 모의실험 결과 제안된 방식은 10개의 비디오를 100의 채널을 이용하여 0.5 requests/second의 도착률로 서비스할 경우 Unified Video-on-Demand 비해 $551{\%}$의 성능향상을 보였다. 본 논문은 동적채널 할당을 이용하여 채널을 해제하고 다시 사용하는 과정, 성능 모델, 모의실험을 제시한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권2호
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• pp.113-121
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• 1994

Large oral defects following tumor resection pose formidable challenge for the reconstructive surgeon. Ideally, wound closure should utilize like tissue in providing expedient, single-stage closure, returning maximum function while minimizing deformity. Recent methods have reported and utilize variable mucocutaneous flaps. However, the ideal reconstruction has yet to defined. The small bowel serves as a readily available donor site for satisfying reconstructive needs in oropharyngeoesophageal defects. Segments of jejunum may be opened along the antimesenteric border and transferred to oral defect as free tissue transfers. Some of the benefits of this technique have included a one-stage procedure, abundant donor tissue with characteristics similar to oral mucosa, near normal facial appearance, preservation of maximum tongue function and relief of annoying xerostomia by jejunal mucous secretion. Three cases re presented in which two cases show successful use of this flap. The other one patient developed total necrosis of this flap. We report cases of reconstruction using free jejunal flap transfer in oral reconstruction.

• Archives of Plastic Surgery
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• 제37권6호
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• pp.801-807
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• 2010

Purpose: Facial rejuvenating surgery has become a challenge to most plastic surgeons. Patients are demanding fewer complications, a prompt recovery, and more natural results. Current trend of the face lift surgery has been developed into less invasive procedures. Every aging patient in Asia wants to look younger without obvious evidence of surgical correction. Methods: The authors performed the limited dissection face lift with PDS quilting suture on twenty five patients. These five quilting sutures consist of sutures at 1~2 cm posterior to the prominent point of zygoma to the periosteum of the zygomatic arch, at the lateral border of Bichat's fat pad area to the zygomatic arch, at the lateral border of the orbicularis oculi muscle to the deep temporal fascia, at the upper lateral border of the platysma to the periosteum of the mastoid, and at the anterior lower margin of the earlobe to the deep temporal fascia by quilting suture technique to achieve rejuvenation. Results: These procedures could produce a balanced volumetric rejuvenation. This method gave considerable benefit of stable and satisfactory results. It provides reduced operative time, well corrected nasolabial fold and neck wrinkle, and swift recovery with minimal complications. Conclusion: Although it could not replace the classic facelift, this technique can be recommended as an option for patients who do not present with advanced facial aging or not want a more extensive procedure.

• Journal of Chest Surgery
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• 제38권6호
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• pp.445-449
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• 2005

부식성 식도협착의 재건수술시 대장의 혈액순환이 나쁜 경우 또는 대장치환술 후 허혈성 부전이 나타난 경우 가장 적합한 재건장기로는 유리공장이식편을 들 수 있다. 복잡하게 합병된 부식성식도협착 환자에서 유리공장이식편을 이용하여 식도재건술을 시행한 4예를 보고하고자 한다. 일차식도재건술로서 4예 중 3예는 대장치환술을, 1예는 장천공에 의한 복막염으로 Whipple's 술식 및 공장루설치술을 받았다. 1예는 인두대장문합부의에 유리공장첩포 이식을, 2예는 대장이식편 부전 부위에 유리공장이식편 치환을 받았다. 1예는 대장의 일부와 유리공장이식편을 이용하여 인두공장대장공장문합술을 시행하였다. 수술 후 문합부위 누출로 인한 재수술이 1예 있었다. 장기추적 관찰상 모두 연하곤란이 없었다. 여러 가지 원인으로 인하여 합병된 식도재건술이 필요하여 유리공장이식편을 사용했던 경우 만족할 술 후 이환율과 연하기능을 보였다.

• 한국군사과학기술학회지
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• 제24권6호
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• pp.664-675
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• 2021

Air force air-to-air combat tactics are occurring at a high speed in three-dimensional space. The specification of the tactics requires dealing with a quite amount of information, which makes it a challenge to accurately describe the maneuvering procedure of the tactics. The specification of air-to-air tactics using natural languages is not suitable because of the intrinsic ambiguity of natural languages. Therefore, this paper proposes an approach of using UML Sequence Diagram to describe air-to-air combat tactics. Since the current Sequence Diagram notation is not sufficient to express all aspects of the tactics, we extend the syntax of the Sequence Diagram to accommodate the required features of air-to-air combat tactics. We evaluate the applicability of the extended Sequence Diagram to air-to-air combat tactics using a case example, that is the manned-unmanned teaming combat tactic. The result shows that Sequence Diagram specification is more advantageous than natural language specification in terms of readability, conciseness, and accuracy. However, the expressiveness of the Sequence Diagram is evaluated to be less powerful than natural language, requiring further study to address this issue.

• Computers and Concrete
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• 제33권5호
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• pp.535-544
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• 2024

In the rapidly advancing landscape of computer vision (CV) technology, there is a burgeoning interest in its integration with the construction industry. Camera calibration is the process of deriving intrinsic and extrinsic parameters that affect when the coordinates of the 3D real world are projected onto the 2D plane, where the intrinsic parameters are internal factors of the camera, and extrinsic parameters are external factors such as the position and rotation of the camera. Camera pose estimation or extrinsic calibration, which estimates extrinsic parameters, is essential information for CV application at construction since it can be used for indoor navigation of construction robots and field monitoring by restoring depth information. Traditionally, camera pose estimation methods for cameras relied on target objects such as markers or patterns. However, these methods, which are marker- or pattern-based, are often time-consuming due to the requirement of installing a target object for estimation. As a solution to this challenge, this study introduces a novel framework that facilitates camera pose estimation using standardized materials found commonly in construction sites, such as concrete forms. The proposed framework obtains 3D real-world coordinates by referring to construction materials with certain specifications, extracts the 2D coordinates of the corresponding image plane through keypoint detection, and derives the camera's coordinate through the perspective-n-point (PnP) method which derives the extrinsic parameters by matching 3D and 2D coordinate pairs. This framework presents a substantial advancement as it streamlines the extrinsic calibration process, thereby potentially enhancing the efficiency of CV technology application and data collection at construction sites. This approach holds promise for expediting and optimizing various construction-related tasks by automating and simplifying the calibration procedure.

• Archives of Plastic Surgery
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• 제42권4호
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• pp.453-460
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• 2015

Background Reconstruction of oropharyngeal defects after resection of oropharyngeal cancer is a significant challenge. The purpose of this study is to introduce reconstruction using a combination of a buccinator myomucosal flap and a buccal fat pad flap after cancer excision and to discuss the associated anatomy, surgical procedure, and clinical applications. Methods In our study, a combination of a buccinator myomucosal flap with a buccal fat pad flap was utilized for reconstruction after resection of oropharyngeal cancer, performed between 2013 and 2015. After oropharyngectomy, the defect with exposed vital structures was noted. A buccinator myomucosal flap was designed and elevated after an assessment of the flap pedicle. Without requiring an additional procedure, a buccal fat pad flap was easily harvested in the same field and gently pulled to obtain sufficient volume. The flaps were rotated and covered the defect. In addition, using cadaver dissections, we investigated the feasibility of transposing the flaps into the lateral oropharyngeal defect. Results The reconstruction was performed in patients with squamous cell carcinoma. The largest tumor size was $5cm{\times}2cm(length{\times}width)$. All donor sites were closed primarily. The flaps were completely epithelialized after four weeks, and the patients were followed up for at least six months. There were no flap failures or postoperative wound complications. All patients were without dietary restrictions, and no patient had problems related to mouth opening, swallowing, or speech. Conclusions A buccinator myomucosal flap with a buccal fat pad flap is a reliable and valuable option in the reconstruction of oropharyngeal defects after cancer resection for maintaining functionality.

• 항공우주정책ㆍ법학회지
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• 제18권
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• pp.385-444
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• 2003

현행 군용항공기지법은 군용항공기의 비행안전과 군용항공기지를 보호하기 위하여 사인의 일정한 행위에 대한 관계행정청의 기타 처분시 사전에 국방부장관 또는 관할부대장과 협의를 거치도록 규정하고 있다. 이러한 협의 절차는 행정절차를 간소화하고, 행정업무처리에 있어서 행정기관사이의 의사통일을 도모한다는 점에서 그 제도적 의의가 있으나, 민 관 군의 이해관계가 대립되는 경우 많은 법적 문제점이 발생된다. 그러나, 이러한 군사협의에 대하여서는 물론이고 행정처분 과정에서 이루어지는 협의에 관해서 학계의 연구가 충분치 못한 상황이다. 본 논문은 이러한 관점에서 협의의견 제출시 관할부대장등에게 재량이 인정되는 지 여부, 협의의견 자체가 위법한 경우 민원인이 이에 대하여 행정쟁송으로 다툴 수 있는 여부, 군용항공기지법상의 협의대상에 관한 몇 가지 문제점, 행정청은 행정처분시 관할부대장등과 협의절차를 거치지 않거나 관할부대장등의 협의의견과 다른 행정처분을 한 경우 그 처분의 효력여하, 이러한 협의의무등을 위반한 행정처분을 시정하는 방법으로서 제거명령 항고소송 권한쟁의심판등에 관한 법적 문제점등을 해결해 보고자 노력하였다.