GMAHN 환경에서의 TCP 프로토콜 성능 분석

吳世德,金玄旭,李光培,張良根,裵振勝,金在浩 明知大學校 産業技術硏究所 2007 産業技術硏究所論文集 Vol.26 No.-

Recently, GMAHN that provides interface between MANET and Wired Network has been focused in Mobile Communication. It is necessary that The technology provide reliable data transmission technology between mobile node and wired network in MANET environment that varing by the node movement. In this paper, using the TCP protocol(Tahoe, Reno, Vegas, SACK)that increases reliability between source and destination, we applied the TCP protocol mechanism to various environment, and compared result, and also proposed the efficient TCP mechanism by comparing each mechanism.

H-pile의 지지력 특성 및 동역학적 공식의 신뢰도 평가

오세욱,이준대 한국산업안전학회 2003 한국안전학회지 Vol.18 No.1

Recently, pile foundations were constructed in rough or soft ground than ground of well condition thus it is important that prediction of ultimate bearing capacity and calculation of proper safety factor applied pile foundation design. This study were performed to dynamic loading tests for the thirty two piles at four different construction sites and selected pile at three site were performed to static loading tests and then compare with measured value and value of static and dynamic loading tests. The load-settlement curve from the dynamic loading tests by CAPWAP was very similar to the results obtained from the static load tests. Based on dynamic and static loading tests, the reliability of pile-driving formula were analyzed and then suggested with proper safety factor for prediction of allowable bearing capacity in this paper.

관골 축소술에 대한 임상적 고찰

백세민,함정욱,백롱민,오갑선 大韓成形外科學會 1997 Archives of Plastic Surgery Vol.24 No.6

Orientals with prominent cheek bones are aesthetically unpleased. So we have performed reduction malarplasty which consists of medial and lateral malar osteotomies, mobilization of malar complex to more attractive point, and wire fixation through coronal incision on 288 patients from March, 1988 to February, 1997. Results have shown symmetry, natural contour, good patient acceptance, and no significant complication. The concept of 'mobilization of malar eminence to more attractive point' is important because the goal of surgery is not to achieve merely 'flat' malar complex. At the same time various procedures have been also performed to improve facial aesthetics. The simultaneous subperiosteal face life was advantageous especially to aged patients and to those with severe anterior projection of malar eminences. Reduction malarplasty combined with reduction angleplasty and face life is one of the useful way to restore the youthful appearance.

2단 IMDCT Recursive 구조를 이용한 MPEG-2 AAC 복호화기의 필터뱅크 구현

박세기,강명수,오신범,이채욱 대구대학교 정보통신연구소 2003 情報通信硏究 Vol.2 No.1

MPEG-2 AAC(Advanced Audio Coding)는 높은 압축율과 고음질의 특성을 갖는 멀티채널 오디오 압축 표준으로 알려져 있고, 대우 낮은 비트율에서 방송 음질 수준의 오디오를 제공하기 위해서 고해상도 필터뱅크(high-resolution filter bank), 예측기법(prediction), 허프만 부호화(Huffman coding) 등을 결합하여 사용한다. MPEG-2 AAC 필터뱅크에서 부화화기와 복호화기에서 각각 수행하는 MDCT(Modified Discrete Cosine Transform)/ IMDCT(Inverse MDCT) 연산은 특히 많은 연산을 필요로 한다. 본 논문에서는 MPEG-2 AAC 실시간 복호화 시스템을 하드웨어로 구현시 IMDCT의 연산에 적합한 2단 IMDCT의 Recursive 구조를 제안한다. 그리고 메모리와 연산속도, 하드웨어의 복잡도를 기존에 제안된 알고리듬과 비교하였다. MPEG-2 Advanced Audio Coding(AAC) is the uideb used audio standard and offers the high-quality multi-channel surround audio AAC algonthm combines the coding efficiency of a high-resolution filter bank, prediction techniques, and Huffman coding to achieie the broadcast-qualitv audio at very low data rates The foruard and inperse modified discrete transform(MDCT) are two of the most computational) 1 intensive operation in the MPEG-2 AAC In this paper, we propose the suitable recursive structure at IMDCT process for MPEG-2 AAC real-time decoder, and compared the memory, the computation speed and complexity of hardware with the proposed algonsms

신연 신생골형성술을 이용한 하악골의 연장 : 실험적 연구 AN EXPERIMENTAL STUDY

백세민,박재현,오재욱 大韓成形外科學會 1995 Archives of Plastic Surgery Vol.22 No.5

Various techniques such as bone graft, vascularized bone and implantation of synthetic material have been used to reconstruct the mandible but these techniques have their own limitations, that is, bony resorption, infection, donor site morbidity and exposure of implant. These limitations could be, however, overcome when the technique of bone lengthening by distraction osteogenesis, the process of generating new bone by gradual distraction. Bone lengthening by distraction osteogenesis has been performed to reconstruct the deficiency of long bones such as tibia since early twentieth century, and is now widely performed in the field of orthopedic surgery. But applying distraction osteogenesis in reconstructing the mandible has a short history. There are few reports describing the optimal rate of mandibular distraction and it remains also controversial whether the nerve injury occurs during distraction. The purpose of this study is to evaluate the process of new bone formation in the mandible and to exzamine the integrity of inferior alveolar nerve histologically when the distraction rate is 1.6mm per day. Six healthy 15 to 20Kg mongrel dogs served as the experimental animals. Left side periosteal preserving reversed L-shape corticotomy was performed from the antegonial notch, and an external lengthening device (Bonefix 200) was fixed parallel to the inferior border of the mandible. After 5 days of latent period, the mandible was lengthened 1.6mm per day(0.8mm in every 12 hrs) for 20 days and held in external fixation for 6 weeks after which all dogs were sacrificed. The specimens were evaluated anthropometrically, radiologically and histologically. Then the results were as follows; 1) The gain in length ranged from 18mm to 25mm(average 23mm). 2) The newly formed bone showed intramembranous ossification. 2 cases contained island of cartilage. 3) Most of nerve fibers in the elongated inferior alveolar nerve showed myelination and normal structure of axon. New bone formation at the distraction rate over 1 mm per day was favorable and most of the new bone was formed by intramembranous ossification, and also inferior alveolar nerve nearly maintained its integrity after distraction. However more detailed study is necessary to determine the ideal distraction rate and exacts ossification mechanism of the mandible.

신속 조형 모형을 이용한 악 교정 수술의 정확성 예측에 관한 연구

고세욱,오승환 원광대학교 치의학연구소 2003 圓光齒醫學 Vol.12 No.1

Rapid Prototyping(RP) models in facial asymmetry patients are used mainly for assisting diagnosis, planning treatment. It provides an easy way to measure discrepancies due to asymmetry on the model directly, and opportunity to study the bony structures of the patient and to manipulate them as required before the actual surgery. The purpose of this study was to evaluate the surgical prediction of orthognathic surgery using RP model in facial asymmetry patients. In 26 patients with facial asymmetry, We compared patient' cephalogram and skull posterior-anterior view with RP model after surgery. Surgery methods were sagittal split ramus osteotomy(SSRO), intraoral vertical ramus osteotomy(IVRO), inverted L osteotomy, Le Fort I osteotomy. Difference of two groups was analyzed and compared statistically. The results were no difference between patients and RP model statistically. In surgical methods, IVRO was better similar results than other methods. RP model is useful in selection of surgery method and prediction of surgery. In facial asymmetry, we knew that IVRO in mandibular surgery is better method than others.

신속 조형 모형을 이용한 악 교정 수술의 정확성 예측에 관한 연구

고세욱,오승환,민승기 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.4

Rapid Prototyping(RP) models in facial asymmetry patients are used mainly for assisting diagnosis, planning treatment. It provides an easy way to measure discrepancies due to asymmetry on the model directly, and opportunity to study the bony structures of the patient and to manipulate them as required before the actual surgery. The purpose of this study was to evaluate the surgical prediction of orthognathic surgery using RP model in facial asymmetry patients. In 26 patients with facial asymmetry. We compared patient cephalogram and skull posterior-anterior view with RP model after surgery. Surfery methods were sagittal split ramus osteotomy(SSRO), intraoral vertical ramus osteotomy(IVRO), inverted L osteotomy, Le FortⅠosteotomy. Difference of two groups was analyzed and compared statistically. The results were no difference between patients and RP model is useful in selection of surgery method and prediction of surgery. In facial asymmetry, we knew that IVRO in mandibular surgery is better method than others.

사안면열의 임상 치험례(5례 보고)

함정욱,김진오,백롱민,오갑성,백세민 大韓成形外科學會 1997 Archives of Plastic Surgery Vol.24 No.5

The oblique facial clefts, which include Tessier No. 3, 4, and 5 clefts, are a catastrophic facial anomaly. The direction they take may be (oro)naso-ocular or oro-ocular. Although oblique facial clefts had beep reported before, in 1823 Laroche was the first to differentiate between ordinary cleft lip or harelip and clefts of the cheek. All these clefts are rare, their incidence ranging from 0.75 to 5.4 per 1,000 common clefts and only one case was reported in the Korean literature. In general multiple operations are required for the reconstruction of these anomalies and the results in most cases are far from ideal. We have experienced 5 cases of oblique facial cleft with acceptable results.

傾斜荷重이 作用하는 얕은 基礎에 設置된 Geogrid의 補强效果

李鳳職,吳世旭 충주대 산업과학기술연구소 2001 産業科學論文集 Vol.9 No.-

A series of model tests was performed for behaviour characteristics of the shallow foundation on sand and sand-clay using the geogrid-reinforced members. The relative density of soil was made to be 55%, 65%, 75% using raining method and the intervals of geogrid placement was increased by 0.25, 0.333, 0.5 times of the foundation width, respectively. As a results of model tests, average bearing capacity was increased by four times in case of relative density 55% and by three times in case of relative density 75%, indicating higher reinforcing effect at low sand density than at high density. The ultimate bearing capacity of shallow foundation geogrid supported by reinforced sand were determined under various angles of inclined loadings(ψ=0˚, 7˚, 14˚, 21˚, 28˚). Based on the test results, the ultimate bearing capacity increases with increase of relative density of sand and the ultimate bearing capacity ratio (BCRu) decreases with the increase of relative density of sand.

이미지 데이터베이스를 위한 정보 검색 시스템의 설계 및 구현

김만순,오세봉,김미연,민은미,박미영,정문숙,문현수,김상욱 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

This paper presents design and implementation of an information retrieval system for a large volue of an image database. Our system supports three kinds of queries: attribute-based queries, keyword-based queries, and color-based queries. The attribute-based query is the most-typical query that finds target images based on their attribute values. The keyword-based query is to find target images by referring to their description information their attribute values. Finally, the color-based query is to search for target images by comparing the colors of a query image with those of images in the database. In this paper, we presents the system architecture and approaches adopted in our system for supporting the above three queries effectively and efficiently. We also discuss the user interface of our system that enables users to manipulate our system easily and conveniently.