Lightweight Printed Dipole Antenna Array With 3×2 Beamforming Network for Wide UAV Communication Coverage

Dong‑Geun Seo,Jeong‑Soo Park,Gun ‑Ki Lee,Wang‑Sang Lee 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

In this paper, a lightweight printed dipole antenna array with 3×2 beamforming network for wide unmanned aerial vehicle (UAV) communication coverage is presented. The proposed antenna consists of an upper substrate, a lower substrate, and two supports with a microstrip feeding. The upper substrate has a two-element printed dipole antenna array, and the lower substrate includes a beamforming feeding circuit and a ground plane as a refector of the proposed antenna array for gain improvement. For wide beam coverage, the proposed feeding network consists of three RF switches, one Wilkinson power divider, and one 90° hybrid coupler, and generates the wide beam using one broadside beam and two end-fre beams. Measured impedance bandwidth, peak gain, and half-power beamwidth (HPBW) of the proposed array operated from 5.03 to 5.15 GHz are approximately 2 GHz, 4.3 dBi, and 155°, respectively.

경부도상 피판을 이용한 구강내 결손부의 재건

양동규,신상훈,서종천,이성근,김종렬 大韓顎顔面成形再建外科學會 1995 Maxillofacial Plastic Reconstructive Surgery Vol.17 No.3

Various cutaneous as well as myocutaneous flaps have been designed for the reconstruction of tissue defects caused by the excision of oral cancer. Among these flaps, cervical island skin flap have been introduced by Farr et al and more have developed by Tashiro et al. This flap has many advantages. The flap minimizes donor size by use of cervical operation wound, flap size available is adequate for most oral defects and the procedure is relatively simple and time saving. However, this flap is not applicable in patients where there are large tissue defects and metastasis is suspected. We used this flap for it's rapid simple, and effective, primary closure of oral defects after cancer ablation and we have found this flap very useful for the reconstruction of relatively small oral defects.

생활치 미백제가 우치 법랑질의 투명도에 미치는 영향

김동준,김영주,김학근,박은종,서은주,황윤찬,오원만,황인남 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.3

본 연구에서는 현재 임상에서 home bleaching을 위해 사용되고 있는 표백 재료들이 치아 법랑질의 투명도에 어떠한 변화를 일으키는지 고찰해 보고자 시행하였다. 실험 대상으로는 하루 전 발거한 우치 (bovine tooth)를 사용하였다. 치아의 순면에 수직되게 다이아몬드 드릴을 이용해 수주 하에서 직경 6 mm의 원통형 치아 시편을 만들어 순면이 노출된 상태로 투명한 아크릭 레진에 포매한 후, low speed diamond saw (Isomat, Buehler Co., USA)를 사용하여 1.2 mm 두께로 절단하였다. 절단된 시편은 순면을 먼저 편평하게 연마하고,절단된 면을 연마하여 두께 1 mm의 시편을 완성하였다. 완성된 시편(우치 25개)을 무작위로 추출하여 3개의 그룹으로 나누고 나머지는 대조군으로 하였다. Opalescence (10% carbamide peroxide, Ultradent, Milford, USA), Rembrandt (10% carbamide peroxide, DenMat, USA) 및 Opalescence F(15% carbamide peroxide with fluoride, Ultradent)를 시편의 순면에 1주일 동안 적용 (표백제는 24시간마다 교체)하였고, 설측면은 증류수를 적신 거즈에 접촉된 상태로 보관하였다 표백제를 적용하기 전과 적용 3, 5, 7일째에 시편의 삼자극치 X, Y, Z 값을 색채색차계 (Color & Color Differencemeter, Model TC-6FX, Tokyo Denshoku Co., Japan)로 백색 배경판과 흑색 배경판 상에서 측정하였다 백색 배경판과 흑색 배경판 상에서 측정된 Y값의 평균값을 이용해 contrast ratio를 계산하였다 얻어진 값을 One Way Repeated Measured ANOVA를 이용하여 통계 처리한 결과 10% Opalescence처치군, 15% Opalescence-F처치군 및 대조군에서는 통계적으로 유의할만한 증감을 보이지 않았고, Rembrandt처치군에서는 Contrast ratio가 증가하였다 (p < 0.01) . This study was done to evaluate whether vital bleaching agents could influence on the translucency of the bovine enamel. The anterior bovine teeth that were extracted one day before and without any gross discoloration were obtained and then were preserved in physiologic saline. 6 mm cylindrical tooth specimens were fabricated with diamond puncher perpendicularly on labial surface of bovine tooth. After embedded in transparent acrylic resin with labial surface being exposed, they were cut to a thickness of 1.2 mm with low speed diamond saw (Isomat, Buehler Co., Lake Bluff, IL, USA). They were smoothly ground to 1 mm thickness of enamel with sandpaper. 24 specimens were randomly divided into 3 groups and control group respectively. Opalescence (10% carbamide peroxide, Ultradent, South Jordan, USA), Rembrandt (10% carbamide peroxide, DenMat, USA) and Opalescence F (15% carbamide peroxide with fluoride, Ultradent, USA) were applied on labial sides of the bovine enamel for 7 days (bleaching agents were reapplied every 24 hours) and the opposite surface was contacted to cotton that soaked in distilled water. The control group was soaked in distilled water. Three stimulus value X, Y and Z were evaluated with colorimeter (Color ' Color Differencerneter, Model TC-6FX, Tokyo Denshoku Co., Japan) on the labial surface of all specimen three times on white and black background plate before the bleaching agents were applied and on 3rd, 5th and 7th day after applied. The degree of translucency was normally assessed by measuring the inverse property, opacity (contrast ratio). 10% Opalescence, 15% Opalescence-F, and control group showed no significant variation in the translucency of bovine enamel, However Rembrandt decreased the translucency of it (p < 0.01).

Carbachol에 의한 닭 췌조직내 nitric oxide synthase 활성 및 methylated arginine 함량변화

유세근,남석우,박승희,남태균,서동완,한정환,홍성렬,이향우 성균관대학교 약학연구소 1994 成均藥硏論文集 Vol.6 No.1

The role of nitric oxide (NO) in the regulation of exocrine secretion was investigated in chicken pancreatic tissues. Nitric oxide synthase (NOS) in the pancreatic tissues were Ca^2+-dependent form. Treatment of tissue with L-arginine (10 mM) or carbachol (10^-5 M) showed the increase of pancreatic exocrine secretion, but that of D-arginine (10 mM) did not. ^3H-citrulline formation, cyclic GMP level and methyl arginine contents in the homogenates of pancreatic tissues treated with carbachol were not affected. Although the action mechanism of NO in the pancreatic tissues remains unknown, NO apparently participates significantly in the overall control of pancreatic secretory function.

저주파음에 의한 자리돔, Chromis notatus의 청각능력 : 청각문턱치

이창헌,서익조,오승훈,김병엽,서두옥,김동근 제주대학교 해양연구소 2001 해양자원연구소연구보고 Vol.25 No.-

제주도 연안 갈치, Trichiurus lepturus 채낚기 어구의 생력화 : 3. 집어등의 수중조도

오승훈,서익조,김병엽,이창헌,정용진,서두옥,김동근 제주대학교 해양연구소 2001 해양자원연구소연구보고 Vol.25 No.-

저주파음에 의한 자리돔, Chromis notatus의 청각 능력 : 청각 문턱치

이창헌,서익조,오승훈,김병엽,서두옥,김동근 제주대학교 해양과환경연구소 2001 해양과환경연구소 연구논문집 Vol.25 No.-

In order to obtain the fundamenal data about method of luring fish schools by underwater sound, this experiment was carried out to investigte the auditory threshold of coralfish Chromis notatus which was on the coast of Jeju island by heartbeat conditioning technique using pure tones coupled with a delayed electric shock. The coralfish could hear a sound in the frequency range from 80 ㎐ to 800 ㎐. The mean auditory thresholds of coralfish at the frequencies of 80 ㎐, 100 ㎐, 200 ㎐, 300 ㎐, 500 ㎐ and 800 ㎐ were 100 ㏈, 99 ㏈, 91 ㏈, 88 ㏈, 96 ㏈ and 114 ㏈, respectively. As the frequency became higher than 300 Hz the auditory threshold increased rapidly.

중소기업형 CIM시스템 구축을 위한 생산계획수립 및 실적파악 모듈

최후곤,신완선,장중순,서준성,여명구,안동근,김진봉 成均館大學校 科學技術硏究所 1996 論文集 Vol.47 No.2

This study Focuses on developing several modules involved in an integrated production information system for medium- or small-sized industries. The modules of order management, quality control, production scheduling, and shop management are executed for an example case industry. The potential values of this research includes that the major information modules to collect, analysis, and display production data and shop data for constructing the computer integrated manufacturing system(CIMS) are programmed with various features of medium- or small-sized industries

Seasonal Changes of Characteristics in Shoot Growth and Canopy Share according Tree Vigor in Apple

Dong Geun Choi,Chong Hyeon Kwon,Chan Suk Seo,Young Min Choi,Ju Hee Song,Byeong Sun Seo 한국원예학회 2008 한국원예학회 기타간행물 Vol.- No.-

Anterior cruciate ligament femoral-tunnel drilling through an anteromedial portal: 3- dimensional plane drilling angle affects tunnel length relative to notchplasty

( Dong-kyu Moon ),( Ho-seung Jo ),( Dong-yeong Lee ),( Dong-geun Kang ),( Hee-chan Won ),( Min-seok Seo ),( Sun-chul Hwang ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Background: Notchplasty is a surgical technique often performed during anterior cruciate ligament reconstruction (ACLR) with widening of the intercondylar notch of the lateral distal femur to avoid graft impingement. The purpose of this study was to correlate femoral-tunnel length with 3-dimensional (3D) drilling angle through the anteromedial (AM) portal with and without notchplasty. Materials and methods: Computer data were collected from an anatomical study using 16 cadaveric knees. The anterior cruciate ligament (ACL) femoral insertion was dissected and outlined for gross anatomical observation. The dissected cadaveric knees were scanned by computed tomography (CT). Three-dimensional measurements were calculated using software (Geomagic, Inc., Research Triangle Park, NC, USA) and included the center of the ACL footprint and the size of the ACL femoral footprint. The femoral-tunnel aperture centers were measured in the anatomical posterior-to-anterior and proximal-to-distal directions using Bernard’s quadrant method. The ACL tunnel was created 3-demensionally in the anatomical center of femoral foot print of ACL using software (SolidWorks®, Corp., Waltham, MA, USA). The 8-mm cylinder shaped ACL tunnel was rested upon the anatomical center of the ACL footprint and placed in three different positions: the coronal plane, the sagittal plane, and the axial plane. Finally, the effect of notchplasty on the femoral-tunnel length and center of the ACL footprint were measured. All the above-mentioned studies performed ACLR using the AM portal. (Continued from previous page) Results: The length of the femoral tunnels produced using the low coronal and high axial angles with 5-mm notchplasty became significantly shorter as the femoral starting position became more horizontal. The result was 30.38 ± 2.11mm on average at 20° in the coronal plane/70° in the axial plane/45° in the sagittal plane and 31.26 ± 2.08mm at 30° in the coronal plane/60° in the axial plane/45° in the sagittal plane, respectively, comparing the standard technique of 45° in the coronal/45° in the axial/45° in the sagittal plane of 32.98 ± 3.04 mm (P < 0.001). The tunnels made using the high coronal and low axial angles with notchplasty became longer than those made using the standard technique: 40.31 ± 3.36mm at 60° in the coronal plane/30° in the axial plane/45° in the sagittal plane and 50.46 ± 3.13mm at 75° in the coronal plane/15° in the axial plane/45° in the sagittal plane (P < 0.001). Conclusions: Our results show that excessive notchplasty causes the femoral tunnel to be located in the nonanatomical center of the ACL footprint and reduces the femoral-tunnel length. Therefore, care should be taken to avoid excessive notchplasty when performing this operation.