900MHz RFID 표준 프로토콜(ISO/IEC 18000-6 type B)에서의 충돌방지 성능 개선

권대근,김완진,김형남,Kwon Dae-Ken,Kim Wan-Jin,Kim Hyoung-Nam 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.5C

본 논문에서는 900 MHz RFID 표준 프로토콜 중 하나인 ISO/IEC 18000-6 type B 프로토콜의 충돌방지 알고리즘의 성능을 분석하고, 이에 대한 성능 향상 방법을 제안한다. 제안된 방법은 ISO/IEC 18000-6 type B 프로토콜의 충돌방지 알고리즘에서 명령 전송 횟수 및 전송 데이터의 양을 줄임으로써 태그 인식 속도를 개선한다. 시뮬레이션 결과를 통해 제안된 방법이 리더 인식 영역 내의 태그 개수와 관계없이 태그 인식 속도를 기존 방법에 비해 21.7% 향상시킬 수 있음을 보인다. This paper proposes a novel anti-collision method for the ISO/IEC 18000-6 type B protocol which is the standard protocol of the 900 MHz RFID system. We improve the anti-collision performance by reducing the transmission number of commands and the length of bits required for multi-tag identification in the ISO/IEC 18000-6 type B protocol. Simulation results show that the proposed method improves the multi-tag identification time by 21.7% over the conventional method, irrespective of number of tags.

측완피판(Lateral upper arm free flap)을 이용한 구강내 결손부의 재건

권대근(Tae Geon Kwon),이상한(Sang Han Lee),R Schmelzeisen,N-C.Gellrich 대한구강악안면외과학회 1999 대한구강악안면외과학회지 Vol.25 No.3

1997년 4월부터 1998년 8월까지 독일 Freiburg 대학에서 행하여진 20증례의 측완피판(Lateral upper arm free flap)을 대상으로 수술증 임상적 소견과 피판생존률, 술후 합병증등의 술후 경과를 관찰하여 다음과 같은 결과를 얻었다. 1. 한 증례의 피판의 완전괴사와 한 증례의 부분괴사를 제외하고 측완피판은 구강내 결손부 재건에 수혜부와 양호한 적합을 이루었으며 저작, 연하등의 기능적 재건에 적합한 정도의 두께와 크기를 제공하였다. 2. 공여부의 감각이상을 보인 증례가 전체의 40%를 차지하였으나 이로인한 불편감을 호소하는 환자는 없었으며 Radial n. 의 손상이나 심한 반흔을 보이지 않았다. 3. 측완피판은 과거 구강악안면부위 결손부의 수복에 주로 이용된 전완피판의 새로운 대안이 될 수 있으나 혈관경의 직경이 작아 수술에 다소의 숙련도를 요하는 것으로 사료된다. Thin and pliable fasciocutaneous free flap is recommended to reconstruct the intraoral defects of intraoral mobile structures to maintain function at optimum. Recently, radial forearm free flap is one of the popular flaps for intraoral reconstruction for these reasons. However, donor site morbidity such as necessary skin grafting and esthetic compromise was the problems of this flap. In this point of view, lateral upper arm free flap(LUFF) has many advantages include relatively simple vascular anatomy and very low doner site morbidity. The purpose of this study is to investigate the 20 consecutive LUFF and evaluate the surgical procedure and postoperative results. The lateral arm flap provided a good functional and esthetic result except for one case of complete flap necrosis because of vascular insufficiency of the supplying vessel of the neck. Although post-operative lower arm partial sensory deficit is a possible disadvantage of this flap, it is a highly reliable method for oral reconstruction with minimal complication.

Cone beam computed tomography로 합성된 두부규격 방사선사진에서의 각 계측점의 정확도와 재현성에 관한 연구

권대근(Dae-Keun Kwon),민승기(Seung-Ki Min),전인철(In-Chul Jun),팽준영(Jun-Young Paeng) 대한구강악안면외과학회 2010 대한구강악안면외과학회지 Vol.36 No.2

Introduction: Cone beam computed tomography (CBCT) has various advantages and is used favorably in many fields in dentistry. Especially, CBCT is being used as basic diagnostic tool for 3-dimensional analysis in orthognathic patient. Two-dimensional cephalograms can be synthesized from CBCT digital imaging and communications in medicine (DICOM) data. In this study, conventional cephalograms and CBCT were taken simultaneously, and representative landmarks were located and analyzed in its accuracy and reproducibility. Materials and Methods: Ten patients who had orthognathic surgery in Wonkwang University Daejeon Dental Hospital participated in this study. For each patient, CBCT and conventional cephalogram was taken. By using Ondemand (Cybermad, Korea), 2-dimensional cephalograms was established on CBCT. In addition, 19 landmarks were designated and measured by 3 orthodontists twice a week. After these landmarks were transferred to a coordinate, distance of landmark and axis, standard error, distribution degree were measured, compared and analyzed. Results: Comparing the CT ceph group and conventional cephalogram group, CT ceph group had shown shorter distance of landmark and axis in S, Hinge axis, Bpt, Ba, Or, Corpus left. Standard error of the mean shows that CT ceph group has better reproducibility in Or, Corpus left, Hinge axis at X axis and Na, U1R, U1T, Bpt, PNS, Ba Corpus left, Hinge axis at Y axis. In both groups, mean error was less than 1.00 mm, no significant difference were found between CT ceph group and conventional cephalogram group in all measurements. Furthermore, comparing two groups, each 17 landmarks out of 19 had its characteristic in distribution degree. Conclusion: No significant difference were found between CBCT composed cephalographic radiograph and conventional cephalograghic radiograph, clinical application may be possible if improved.

상악결손부의 2차적 재건에 있어 유리 혈관화 피판의 적용

권대근(Tae-Geon KWON),김진수(Chin-Soo KIM) 대한치과의사협회 2011 대한치과의사협회지 Vol.49 No.9

Microvascular reconstruction of maxillary composite defect after oncologic resection has improved both esthetic and functionai aspect of quality of life of the cancer patients. However, a lot of patients had prior surgery with radiation and/or chemotherapy as a part of comprehensive cancer treatment. Sometimes it is nearly impossible to find out adequate recipient vessel for maxillary reconstruction with microvascular anastomosis. Therefore long pedicle of the flao is needed to use distant neck vessels located far from the reconstruction site such as ipsilateral transverse cervical artery or a branch of contralateral external carotid artery. For this reason, although we know the treatment of the choice is osteocutaneous flap, it is difficult to use this flap when we need long pedicle with complex three dimensional osseous defect. Vascular option for these vessel-depleted neck patients can be managed by a soft tissue reconstruction with long vascular pedicle and additional free non-vascularized flap that is rigidly fixed to remaining skeletal structures. For this reason, maxillofacial reconstruction by vascularized soft tissue flap with or without the secondary restoration of maxillary bone with non-vascularized iliac bone can be regarded as one of options for reconstruction of profound maxillofacial composite defect resulted from previous oncological resection with chemoradiotherapy.

구순구개열환자에 대한 악교정수술후 안정성에 대한 연구

권대근(Tae Geon Kwon),森悅秀(Yoshihide Mori),南克浩(Katsuhiro Minami),김종배(Jong Bae Kim) 대한구강악안면외과학회 2000 대한구강악안면외과학회지 Vol.26 No.4

To evaluate the stability after orthognathic surgery in cleft lip and palate patients using rigid fixation, 20 patients underwent primary repair in childhood and later developed a jaw deformity and malocclusion that required orthognathic surgery were reviewed. Two groups, one of 10 patients performed Le Fort I osteotomy with sagittal split ramus osteotomy and one of 10 patients with sagittal split ramus osteotomy of the mandible, were evaluated. Each group had unilateral cleft only and all alveolar cleft sites had been grafted with autogeneous bone before the orthognathic surgery. The amount of surgical movement and relapse were compared in both horizontal and vertical dimensions. Two-jaw surgery group was more stable than mandibular surgery only group in mandibular position (p< 0.05). Statistically significant relapse was observed in mandibular skeletal point in mandibular surgery group (p<0.05). There was no statistically significant relapse in the skeletal point of two-jaw surgery group. However, the correlation between the horizontal surgical movement and relapse was detected (r = 0.88). This correlation indicates the need of overcorrection. The presence of scar tissues and relatively deficient maxillary bone could be attributed to this close relation between the surgical change and relapse.

지상파 DMB 전송 속도 향상을 위한 Amplitude-DQPSK 변조 기법

권대근(Dae-Ken Kwon),김형남(Hyoung-Nam Kim),임형수(Hyoungsoo Lim),임종수(Jong Soo Lim) 제어로봇시스템학회 2006 제어로봇시스템학회 합동학술대회 논문집 Vol.2006 No.12

임플란트 식립후 하악 신경손상에 대한 후향적 연구

권대근(Tae-Geon Kwon),김신유(Shin-Yu Kim),김종배(Jong-Bae Kim) 대한구강악안면외과학회 2004 대한구강악안면외과학회지 Vol.30 No.4

The purpose of this study was to evaluate neurosensory disturbance associated with implant surgery performed by implant practitioner(n=47) composed of trained oral surgeon, periodontist, prosthodontist. The incidence, type and duration of sensory disorder were investigated. Anatomical factor of the patient and experience of operator were also evaluated. The result revealed high incidence of inferior alveolar nerve damage (45%) regardless of experience of implant practitioner. The sensory disturbance sustained within 6 months for 61% of cases, which revealed almost normal recovery of nerve function. Initial neurologic sign after nerve damage was not coincide with their consequence of recovery. Half of the practitioners tried surgical intervention to the implants such as removing the fixture, partial unscrewing or re-implant shorter fixture, of which trial regarded as effective measure for 53% of cases. The result indicates that the objective method of sensory nerve evaluation should be introduced to the implant practitioners and the importance of informed consent for possibility of nerve damage in mandibular implant fixation.

UHF RFID 표준 프로토콜(ISO 1800-6B)에서의 충돌방지 성능개선

권대근(Dae-Ken Kwon),김완진(Wan-Jin Kim),이유석,김형남(Hyoung-Nam Kim) 한국통신학회 2005 한국통신학회 학술대회논문집 Vol.2005 No.11

구강암의 연구동향 및 임상적 의의

권대근(Tae-Geon Kwon),김진수(Chin-Soo Kim) 대한치과의사협회 2010 대한치과의사협회지 Vol.48 No.8

Recent advancement in molocular biology enhanced further understanding of the carcinogenesis of oral cancer and its relation with various genetic backgrounds. Familial risk factors includes similar habits of the family and polymorphic variations of the genes. Recently, human papilloma virus has been suggested to be linked with oral cancer progression. Enhancement of understanding of the damage or alteration in molecular pathway in various cellular response of oral cancer progression would lead the targeted therapy or precise early diagnosis of the oral cancer.

안전한 택시이용을 위한 시스템 및 앱 설계

권대근 ( Dae-geun Kwon ),홍석기 ( Seok-gi Hong ),박건훈 ( Geon-hun Park ),정세훈 ( Se-hun Jung ),임대준 ( Dae-jun Lim ),임양원 ( Yang-won Lim ),임한규 ( Han-kyu Lim ) 한국정보처리학회 2013 한국정보처리학회 학술대회논문집 Vol.20 No.2

택시는 많은 사람들이 이용하고 있는 교통수단이다. 특히 버스나 지하철 같은 대중교통 운행시간이 끝나는 야간에는 택시의 이용률이 더 많을 수밖에 없다. 그러나 최근 택시를 이용한 범죄가 많이 발생하면서 택시에 대한 사람들의 불안감이 커져가고 있다. 본 논문에서는 스마트폰을 이용하여 택시를 보다 안전하게 이용할 수 있는 시스템과 앱을 설계하였다. 스마트폰의 NFC 기술을 이용하여 인증된 택시에 부착된 NFC 태그를 인식하게 되면 택시정보와 탑승정보를 미리 등록된 지인들에게 실시간으로 전송하게 된다. 그로 인해 탑승자들은 보다 더 안전하게 택시를 이용하게 될 것을 기대할 수 있다.