• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
• /
• pp.293-296
• /
• 2005

This paper presents the design of linear and circular polarization baseball- shaped circular microstrip antenna (BCMA) with 3-dimensional structure using perturbation effect to reduce its size, which runs at 1.575GHz frequency bandwidth. As a result, the size of linear polarized antenna could be reduced up to 23.7% in patch diameter and 41.8% in its area. Linear polarized antenna has -26.04dB of return loss, 69MHz(4.38%) of -l0dB bandwidth, 4.51dBd of gain, and its -3dB beamwidth are 99$^{\circ}$ in E-plane, 83$^{\circ}$ in H-plane. Circular polarized antenna has -17.43dB of return loss, 113.7MHz(7.2%) of -l0dB bandwidth, 2dBd of gain, 2dB of axial ratio and its -3dB beamwidth are 87$^{\circ}$, 86$^{\circ}$ x-axis polarized, 80$^{\circ}$, 84$^{\circ}$ y-axis polarized. It has 82mm of diameter, which is 28.5% of linear polarized CMPA. Therefore, in this paper we verified that baseball-shaped 3-dimensional structure of circular microstrip patch antenna applied with perturbation effect is appropriate for miniaturization.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제33권2호
• /
• pp.137-143
• /
• 2011

Purpose: Orthognathic surgery is required in patients with severe skeletal disharmony and facial asymmetry, which results in functional and esthetic improvement. Recently, bimaxillary surgery has become generalized. Establishment of the occlusal plane among several other factors included in the surgery plan is a major consideration for the diagnosis and treatment plan and it is also an important factor for postoperative stability. Methods: In this study, we assessed postoperative stability of occlusal plane, B-point, and pogonion point on 20 patients who underwent two-jaw surgery in the Chosun Dental Hospital from 2000 to 2007. Preoperative and postoperative states and at least a one year postoperative follow-up were compared. Results: The postsurgical relapse volume of the occlusal plane to the SN plane and the FH plane was $-0.26{\pm}2.8^{\circ}$ and $-0.44{\pm}3.29^{\circ}$, respectively and after two-jaw surgery, the stability of occlusal plane was maintained. The horizontal relapse degree was $0.85{\pm}0.46$ mm and $0.76{\pm}0.48$ mm, respectively, and the vertical relapse degree was $1.16{\pm}0.36$ mm and $1.13{\pm}0.71$ mm of the B point and the Pogonion point at the time after minimal 1 year. Conclusion: The vertical relapse amount was shown to be slightly larger than the horizontal relapse amount.

• 한국전자파학회논문지
• /
• 제21권7호
• /
• pp.786-795
• /
• 2010

본 논문에서는 EBG(Electromagnetic Band Gap) 구조에 존재하는 두 단위 셀을 신호 전달 평면상의 브릿지 라인으로 연결하는 새로운 형태의 EBG 구조를 제안하였다. 이와 같은 구조를 갖는 EBG는 단위 셀을 연결하는 비아 홀과 브릿지 라인으로 인해 전원면에서 SSN(Simultaneous Switching Noise)를 효과적으로 차단하였으며, 또한 신호 평면상에서 존재하는 신호선들 사이에서는 우수한 신호 전달 특성을 보였다. 제안된 구조의 EBG는 특정 사이즈에서 차단 주파수 1.2 GHz, 저지 대역폭은 8.3 GHz로 넓은 주파수 대역에서 －30 dB 이하의 저지 대역특성을 나타내었다. 또한 광대역의 저지 대역폭을 유지하면서 신호 평면상에 위치한 신호선이 우수한 신호 전달 특성을 가질 수 있는 전원면/접지면의 위치를 최종적으로 제안하였다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제19권1호
• /
• pp.25-34
• /
• 1997

This study was made with lateral cephalometric radiography of 28 skeletal class III malocclusion patients that were performed to setback surgery of mandible. The 28 patients were selected by four standards as follows. 1) Set-back amount of mandible is below 10 mm 2) No extrusion and intrusion of posterior tooth or alteration of interincisial angle at period of postoperative orthodontic treatment. 3) Change of mesial segment location of mandible on lateral cephalometrics 4) No genioplasty And 28 patients were divided to three group(1,2,3 group) by degree of preoperative occlusal plane angle to Burstone's horizontal plane. The preoperative occlusal plane angle, which of 1 group was smaller than $7^{\circ}$ and 2 group was between $7^{\circ}$ to $15^{\circ}$ and 3 group was larger than $15^{\circ}$. The results were as follows : 1. As the preoperative occlusal plane angle was larger, the degree of mandibular prognathism was not severe. 2. On comparsion of preoperative and immediate postoperative cephalometric analysis, specific relationship of occlusal plane angle and set-back amount of mandible was not present. 3. As the preoperative occlusal plane angle was smaller, the alteration of postoperative occlusal plane angle was increased tendency. As the preoperative occlusal plane angle was larger, the alteration of postoperative occlusal plane angle was decreased tendency. 4. The relapsed degree of B point distance to Vertical plane was not relationship to the degree of preoperative occlusal plane angle.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권10호
• /
• pp.1407-1413
• /
• 2005

An experiment was conducted in order to assess the effect of level of RDP:UDP ratio and level of feeding concentrate on milk yield, milk composition and nutrient utilization in lactating crossbred cattle. Twenty four medium producing (-10 kg/d, 45 to 135 days postpartum) lactating crossbred cows were divided into four groups of six animals each in a 2${\times}$2 factorial completely randomized design. The cows in group 1 were fed concentrate mixture I containing 59:41 RDP:UDP ratio (low UDP) at normal plane (LUDP+NP), in group 2 were fed low UDP ration at 115% of NRC (1989) requirements (LUDP+HP), whereas cows in group 3 were fed concentrate mixture II containing 52:48 RDP:UDP ratio (high UDP) at normal plane (HUDP+NP) and in group 4 were fed high UDP ration at 115% of NRC (1989) requirements (HUDP+HP). Green jowar was fed ad libitum as the sole roughage to all the animals. The experimental feeding trial lasted for 105 days. The total dry matter intake (DMI), DMI/100 kg body weight, DMI/kg $W^{0.75}$, digestibilities of DM, OM, CP, CF, EE and NFE and intakes of TDN and DCP did not differ significantly among the different groups and also due to both UDP level and plane of nutrition and also due to their interaction. The total dry matter intake varied from 145 g in group 1 (LUDP +NP) to 152.57 g/kg $W^{0.75}$ in group 2 (LUDP+HP) diet. However, increase in milk yield with increased UDP level and also with increased plane of nutrition was observed consistently throughout the experimental period. The average milk yield was 7.66, 8.15, 8.64 and 9.35 kg in groups 1, 2, 3 and 4, respectively and there was no significant difference in milk yield among different groups of cows. The overall daily average milk yields in cows fed with low and high UDP diets were 7.91 and 8.99 kg, respectively and at normal and higher plane of feeding the milk yields were 8.15 and 8.75 kg/day, respectively. Thus, there was 13.65% increase in milk yield due to high UDP level and 7.36% due to higher plane of feeding. The daily 4% FCM yields were 9.20 kg for low UDP diet and 10.28 kg for high UDP diet, whereas it was 9.11 kg at normal plane of feeding and 10.37 kg at higher plane of feeding. Fat yields for the corresponding treatment groups were 0.37, 0.43, 0.41 and 0.48 kg, respectively. The 4% FCM yield and also fat yield did not differ significantly among different dietary treatments and also due to UDP level and plane of nutrition, however, 4% FCM yield was increased by 11.74% with high UDP level and 13.83% with higher plane of feeding. The values for total solids, fat, lactose, solids-not-fat and gross energy contents in milk differed significantly (p<0.05) among the different groups and were significantly (p<0.05) higher in milk of cows fed LUDP+HP diet followed by HUDP+HP diet. Total solids (14.65 and 13.83%), lactose (5.44 and 4.92%), solids-not-fat (9.44 and 8.83%) and gross energy (887 and 838 kcal/kg) of milk decreased significantly (p<0.05) with increased UDP level while total solids (13.84 and 14.64), fat (4.84 and 5.36%) and gross energy (832 and 894 kcal/kg) increased significantly (p<0.05) with increase in plane of feeding. Gross and net energetic efficiencies and also gross and net efficiencies of nitrogen utilization for milk production were not significantly different among different groups and also were not affected significantly due to either UDP levels or plane of feeding. Results of the present study suggest that, increasing UDP level from 41% to 48% of CP in concentrate mixture and also increasing plane of feeding from normal (100%) to 115% of NRC requirements maintain a consistently higher milk production.

• 한국전자파학회논문지
• /
• 제12권3호
• /
• pp.425-431
• /
• 2001

비유전율 ${\epsilon}_{r}$=36인 유전체를 이용한 무선 LAN용 개구 결합 마이크로스트립 원통형 유전체 공진 안테나(DRA)를 설계하고 제작하였다. 우선 급전 소자는 마이크로스트립 전송선로 이론을 이용하여 급전 선로 길이, 선로 폭, 슬롯 길이, 슬롯 폿과 스터브 길이을 계산하였다. 방사 소자는 원통형 유전체 cavity 이론을 이용하여 설계하였다. 제작된 원통형 DRA의 공진주파수는 2.449 GHz이고 VSWR, 반사 손실과 대역폭은 각각 1.009, -47dB 와 70MHz이다. 방사 패턴의 전후방비는 13dB이고 E면과 H 면의 3dB 빔폭은 각각 1$10^{\circ}$과 90$^{\circ}$이다.

• 한국전자파학회논문지
• /
• 제12권1호
• /
• pp.125-135
• /
• 2001

본 논문에서는 SAR(Synthertic Aperture Radar) 시스템에 적합한 이중편하 하중 지지형 마이크로스트림 8$\times$4 배열 안테나를 설계, 제작하여, 그 측정 결과를 시뮬레이션 결과와 비교하였다. 안테나 설계 시 운용 주파수와 대역폭, polarization putity, -3 dB 빔 폭 등과 같은 전기적 특성뿐만 아니라, 구조적 안정성, 강도, 강성 등의 기계적 특성을 함께 고려하였다. 본 안테나는 SSFIP 형 구조에 허니콤과 Shielding plane을 첨가한 형태이며, 이중편파는 서로 수직으로 위치한 두 개의 dog-bone shape 슬롯으로 구현하였다. 각 실험 결과로부터 제안한 안테나 중심 주파수 5.3 GHz를 중심으로 약 80GHz 의 대역폭을 지니고, -20 dB 이하의 cross-polarization level, 약 40dB 정도의 포트간 고립도 특성을 타나내며 구조적으로도 안정됨을 알 수 있었다.

• 한국군사과학기술학회지
• /
• 제9권3호
• /
• pp.101-108
• /
• 2006

This paper describes the design, fabrication, and measured results of a W-band Cassegrain antenna suitable for the target detecting fuze sensor. The Cassegrain antenna is designed using MATLAB and MWS of CST. We use the multi-mode horn antenna as a feeder. The measurement results are as follows: The gain is about 41dB; SLL is 17.7dB; 3dB beamwidth is about $1.51^{\circ}$ in E-plane and $1.45^{\circ}$ in H-plane. The magnitude of leakage signals is about 43.5mVpp when the fabricated antenna and the transceiver of the fuze sensor ire combined. As a result, the designed W-band Cassegrain antenna could be quite applicable to the target detecting fuze sensor.

• 제어로봇시스템학회논문지
• /
• 제11권11호
• /
• pp.895-900
• /
• 2005

We derive a linear matrix inequality(LMI) condition guaranteeing that any invariant zeros of a triple (A, B, C) lie in the open left half plane of the complex plane, i.e. $C(sI-A)^{-1}B$ is minimum phase. The LMI condition is equivalent to a certain constrained Lyapunov matrix equation which can be found in many results relating to stability analysis or control design. We show that the LMI condition can be used to simplify various control engineering problems such as a dynamic output feedback control problem, a variable structure static output feedback control problem, and a nonlinear system observer design problem. Finally, we give some numerical examples.

• 한국지반공학회지:지반
• /
• 제10권3호
• /
• pp.111-118
• /
• 1994

A series of drained cubical triaxial tests was performed to investigate the finfluence of the intermediate principal stress on the deformation and strength characteristics of sand. Test results showed that the strength of sand as represented by the friction angle increased from triaxial compression condition (b:0) with increasing magnitude of the intermediate principal stress until the vus of b reached 0.75, land it decreased slightly with closing to b= 1. Also it was found that the projection of the plastic strain increment vector on the octahedral plane was perpendicular to the trace of the failure surface on that plane. The prediction by the isotropic single hardening model sllowed good coinidence with experimental results.