• 한국조명전기설비학회지:조명전기설비
• /
• 제2권2호
• /
• pp.55-58
• /
• 1988

관벽온도에 따른 형광램프 양광주 내의 전자이동도 변화를 계산하였다. 전자분포 함수는 2 Electron Group Model을 사용하였다. 또한 이를 검증하기 위하여, 38mm 20W 형광램프 양광주 내의 전자이동도를 관벽온도를 변화시키면서 측정하였다. 측정방법으로는 양광주 내의 전계를 구하기 위하여 양극 및 음극 강하전압의 합을 15V로 가정하였으며 2중 슬릿을 사용하여 양광주의 길이를 측정하였다. 관벽온도를 $10-18^{\circ}C$로 변화시키며 계산하고 측정한 결과를 표시하였다.

• 대한토목학회논문집
• /
• 제33권2호
• /
• pp.679-689
• /
• 2013

최근 지구환경 보호를 위한 도시지역의 온실가스 배출량 저감은 중요한 이슈이며, 특히 도시교통에 있어 자가용 이용 저감을 통한 배출량 감소를 위한 정책들이 추진되고 있다. 이러한 도시교통정책 중 대표적인 것이 교통수요관리(Transportation Demand Management; TDM)기법이며 혼잡통행료 부과, 유류세 등 규제를 통해 자가용 이용을 억제하는 방법이다. 반면 사회심리학이론에 바탕한 모빌리티 매니지먼트(Mobility Management; MM)기법은 커뮤니케이션을 통해 자발적 자가용 이용저감을 유도하며, 의사결정과정에 내재되어 있는 심리적 요인에 초점을 두고 있다. TDM기법이 자가용 이용저감에 일정부분 기여하고 있으나 지금까지 자가용 이용의 최종 판단주체인 개인의 의식전환을 통한 자발적 교통행동변화를 유도하는 노력은 미흡하였다. MM기법의 유효성에 대해서는 기존 해외 연구에서 논의된 바가 있으나 아직까지 자발적 행동변화의 의사결정과정에 대한 명시적 분석에 관한 연구는 활발하지 않은 실정이다. 이에 본 연구는 사회심리학이론에 바탕을 둔 MM기법의 중요성과 국내도입을 위한 기초 연구로서 자발적인 자가용 이용저감 행동변화에 대한 의사결정과정 분석을 목적으로 한다. 분석을 위해 사회심리학적 접근방법론의 하나인 구조방정식 모형을 적용하였다. 본 연구의 사례분석을 통해 개인의 의사결정과정에 내재되어 있는 심리적 요인(예, 환경의식, 개인규범 등) 등이 개인들의 자가용 이용 저감에 유효한 영향이 있으며, 규제 중심의 자가용 이용저감 기법뿐만 아니라 MM 도입의 필요성에 대해 논증하였다.

• 전기전자학회논문지
• /
• 제11권4호
• /
• pp.272-278
• /
• 2007

본 논문에서는 최근 고출력 및 고온 분야의 반도체 분야에 널리 이용되고 있는 AlGaN/GaN 고 전자 이동도 트랜지스터 (High Electron Mobility Transistor, HEMT) 에 대해 DC (direct current) 특성과 열 특성을 기판을 달리하며 시뮬레이션을 수행하였다. 일반적으로 HEMT 소자의 전자 이동도 및 열전도 특성은 기판의 영향이 그 특성을 크게 좌우한다. 이러한 문제점으로 인해 GaN 기반의 HEMT 소자의 기판에 대한 연구가 활발히 진행되고 있다. 따라서, 일반적인 Drift-Diffusion 모델과 열 모델을 이용하여 Si, sapphire, SiC (silicon carbide)으로 각각 기판을 변화시키며 시뮬레이션을 하였다. 열 모델 시뮬레이션은 온도를 각각 300, 400, 500K로 변화시키며 그 결과를 비교, 해석 하였다. 전류-전압 (I-V) 특성을 T= 300 K, $V_{GS}$=1 V의 조건에서 시뮬레이션 한 결과, 드레인 포화전류 ($I_{D,max}$)의 값과 sapphire 기판은 189 mA/mm, SiC 기판은 293 mA/mm, Si 기판은 258 mA/mm 를 나타내었다. 또한 T= 500 K에서 최대 전달컨덕턴스($G_{m,max}$)는 각각 38, 50, 31 mS/mm 를 나타내었다.

• 대한기계학회논문집B
• /
• 제25권9호
• /
• pp.1175-1182
• /
• 2001

Chemical compositions of polydisperse SiO$_2$/TiO$_2$multicomponent aggregates were measured for different heights from the burner surface and different mobility diameters of aggregates. SiO$_2$/TiO$_2$multicomponent particles were generated in a hydrogen/oxygen coflow diffusion flame from two sets of precursors: TTIP(titanium tetraisopropoxide), TEOS(tetraethylorthosilicate). To maintain 1:1 mole ratio of TTIP:TEOS vapor, flow rate of carrier gas $N_2$was fixed at 0.6lpm for TTIP, at 0.1lpm for TEOS. In-situ sampling probe was used to supply particles into DMA(differential mobility analyzer) which was calibrated with using commercial DMA(TSI, model 3071A) and classifying monodisperse multicomponent particles. Classified monodisperse particles were collected with electrophoretic collector. The distributions of composition from particles to particle were determined using EDS(energy dispersive spectrometry) coupled with TEM(transmission electron microscope). The chemical(atomic) compositions of classified monodisperse particle were obtained for different heights; z=40mm, 60mm, 80mm. The results suggested that the chemical(atomic) composition of SiO$_2$decreased with the height from burner surface and the composition of SiO$_2$and TiO$_2$approached to the value of 1 to 1 fat downstream. It is also found that the composition of SiO$_2$decreases as the mobility diameter of aggregate increases.

• 대한두개안면성형외과학회지
• /
• 제12권1호
• /
• pp.12-16
• /
• 2011

Purpose: This study examined the biomechanical stability of four different plating techniques in the experimental model of mandibular subcondyle fracture. Methods: Twenty standardized bovine tibia bone samples ($7{\times}1.5{\times}1.0cm$) were used for this study. Each of the four sets of tibia bone was cut to mimic a perpendicular subcondyle fracture in the center area. The osteotomized tibia bone was fixed using one of four different fixation groups (A,B,C,D). The fixation systems included single 2.0 mm 4 hole mini adaption plate (A), single 2.0 mm 4 hole dynamic compression miniplate (B), double fixation with 2.0 mm 4 hole mini adaption plate (C), double fixation with a 2.0 mm 4 hole mini adaption plate and 2.0 mm 4 hole dynamic compression miniplate (D). A bending force was applied to the experimental model using a pressure machine (858 table top system, $MTS^{(R)}$) until failure occurred. The load for permanent deformation, maximum load of failure were measured in the load displacement curve with the chart recorder. Results: Double fixation with a 2.0 mm 4 hole mini adaption plate and a 2.0 mm 4 hole dynamic compression miniplate (D) applied to the anterior and posterior regions of the subcondyle experimental model showed the highest load to failure. Conclusion: From this study, double fixation with an adaption plate and dynamic compression miniplate fixation technique produced the greatest biomechanical stability. This technique may be considered a useful means of fixation to reduce the postoperative internal maxillary fixation period and achieve early mobility of the jaw.

• Journal of Korean Dental Science
• /
• 제15권1호
• /
• pp.61-67
• /
• 2022

Purpose: This study aimed to evaluate the accuracy of bite registration using intraoral scanner based on data trimming strategy for fremitus teeth. Materials and Methods: A reference model was designed by Medit Model Builder software (MEDIT Corp., Seoul). Tooth number 24 and 25 were separated as dies and tooth number 26 was prepared for full-coverage crown. Those were printed using a 3D printer (NextDent 5100). The scanning procedure was performed by a single trained operator with one intraoral scanner (i700; MEDIT Corp.). The scanning groups were divided as follows: group 1 (G1), no fremitus; group 2 (G2), 0.5 mm buccal fremitus in the maxillary left first and second premolar; and group 3 (G3), 1.5 mm buccal fremitus in the maxillary left first and second premolar. Each group was scanned 10 times and were analyzed using the reference model data. Surface-based occlusal clearance was analyzed at the prepared tooth to evaluate accuracy. Result: Mean values of control group (G1) were 1.587±0.021 mm. G2 showed similar values to those from the control group (1.580±0.024 mm before trimming strategy and 1.588±0.052 mm after trimming strategy). G3 showed significantly greater values (1.627±0.025 mm before trimming strategy and 1.590±0.024 mm after trimming strategy) and the differences were found between trimming strategy (P=0.004). Conclusion: Bite trimming strategy for fremitus teeth is a reliable technique to reduce inaccuracies caused by the mobility at maximum intercuspation.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.867-872
• /
• 2007

A tracked robot has an excellent mobility on the rough terrain. Especially, a tracked robot for driving has to get structural function in the every field. In this paper, we propose a tracked robot of a small rear wheel typed. Also compared and estimated a driving analysis about the tracked robot in considered the general environment. Compared 2 models are different in size of rear wheels but front wheels are same size each other. From comparing model, the radius of front wheels is 100mm and the radius of rear wheels is 100mm. The radius of front wheels is 100mm and the radius of rear wheels is 70mm from proposed tracked robot. Depend on these radiuses of values we are known driving torque values of an actuating wheel using Recurdyn. And estimated stress of rotated track by an actuating wheel using Ansys. finally, the designed robot has size of $600mm\;{\times}\;330mm\;{\times}\;150mm$, weight is 27kg and the tracked robot is actuated by 2 geared DC motors.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 2005년도 추계학술대회 및 정기총회
• /
• pp.3-7
• /
• 2005

The structure of $IP^2$(IP based-IMT Network Platform) as ubiquitous platform is three-layered model : Middleware including NCPF(Network Control Platform) and SSPF(Service Support Platform), IP-BB(IP-Backbone), Access network including Sensor network. A mobility management(MM) architecture in NCPF is proposed for $IP^2$. It manages routing information and location information separately. The existing method of multicast control in $IP^2$ is Remote Subscription. But Remote Subscription has problem that should be reconstructed whole Multicast tree when sender moves. To solve this problem, we propose a way to put Multicast Manager in NCPF.

• 대한치과보철학회지
• /
• 제19권1호
• /
• pp.39-45
• /
• 1981

Distal-extension removable partial dentures have long been implicated in the increase in mobility and the destruction of the supporting structures of the primary abutment teeth. Various clasping systems have traditionally been used to retain distal extension removable partial dentures, and other designs have been proposed to minimize torquing forces on the abutment teeth. Most recent studies investigating the effects of removable partial dentures on abutment teeth have been performed in it laboratory setting. Results obtained from in vitro research have given dentists insight into removable partial denture design, but laboratory test model cannot be constructed that simulates actual functional or parafunctiona1 movements and forces. The purpose of this study was to clinically evaluate the degree of tooth mobility produced by two clasping systems (suprabulge type and infrabulge type) used for distal extension removable partial dentures. Akers clasp and R.P.I. system were selected for the evaluation, and four patients required a distal extension removable partial denture on the mandibular arch were selected for participation in the study. Two partial dentures were constructed in the same condition expect the design of clasp. All abutments in the study were mandibular first or second premolars. Measurements of mobility were made with a research tool designed by $M\"{u}hlemann$. This instrument, periodontometer, measures tooth mobility in the mouth by means of a dial gauge accurated to 0.01mm when the tooth is stressed with a force meter. Lingual and buccal deflection of abutment tooth was measured using buccal and lingual pressure. The amount of force applied was 500gm. Tooth mobility tests were made at four key stages; 1. Before insertion of the first removable partial denture, baseline mobility was establsihed. 2. After wearing of the first prosthesis, measurement was made at weekly intervals for 4 weeks. 3. The removable partial denture was then taken from the patient, and tooth mobility was measured again at weekly intervals until the patient's established baseline mobility had returned. 4. The second prosthesis of different clasp design was worn for a month and evaluated in the same manner as the first. The sequence of placement of clasping system was alternated between patients. The following results were obtained from this study; 1. The mobility of abutment tooth increased during the initial stage of wear and returned to baseline mobility after removal of removable partial dentures. 2. The mobility of abutment tooth showed no difference between Akers clasp and I-bar clasp during the 4-week test period. 3. All teeth tested showed greater mobility toward the buccal than the lingual direction.

• International Journal of Internet, Broadcasting and Communication
• /
• 제12권3호
• /
• pp.156-162
• /
• 2020

Wireless Sensor Network (WSN) field is mainly studied to monitor and characterize large-scale physical environments to track various environmental or physical conditions, such as temperature, pressure, wind speed and humidity. WSN can be used in various applications such as wild surveillance, military target tracking and monitoring, dangerous environmental exploration and natural disaster relief. We design probabilistic mobile models that apply to mobile ad hoc network mobile environments. A probabilistic shift model proposed by dividing the number of moving nodes and the distance of travel into two categories to express node movement characteristics. The proposed model of movement through simulation was compared with the existing random movement model, ensuring that the width and variation rate of the first node node node node (FND) was stable regardless of the node movement rate. In addition, when the proposed mobile model is applied to the routing protocol, the superiority of network life can be verified from measured FND values. We overcame the limitations of the existing random movement model, showing excellent characteristics in terms of energy efficiency and stable in terms of changes in node movement.