Dental brackets are widely used by the orthodontists to correct the misalignment of teeth in the mouth over a long period of time. In this study, finite element analysis of orthodontic bracket has been carried out for the observation of the stress distribution and deformation pattern in the different materials bracket (Stainless Steel, Ceramic, Titanium, Polycarbonate and Nitinol) when subjected to arch wire torsion and tipping force. The simulation results were further optimized with respect to bracket attachment surface. It was found that it is possible to know the change in result is correlated with the attachment surface of the stress and deformation due to change in diameter. The results confirmed that the finite element method has proved to be successful for proper design analysis for future development of the teeth bracket.

Structural system involves random conditions such as material property, geometric parameters and applied loads. This is caused by either measurement inaccuracy or system complexity and must be designed to withstand the uncertainties, Random structures may be modelled by using the finite element method using Monte Carlo simulation. It can be applied easily to any structural system with random parameters. The aim of this paper is to find the shape optimal design for the cantilever beam with random input variables to the height and response parameters to the displacement and stresses. The probabilistic design is carried out using ANSYS probabilistic design module in a commercial application software and then the optimal design is sequentially solved. An efficient and practical shape optimal design evaluation method is proposed for the design of the cantilever beam shape. The numerical results are obtained where total volume of the beam, stresses and displacements in the beam treated as constraints

District Metered Area (DMA) construction is one of the most cost effective alternatives for management of water loss (i.e., water leakage) and energy consumption (i.e., water pressure) in water distribution systems. Therefore, it’s being implemented to numerous new and existing water distribution systems worldwide. However, due to the complexity of water distribution systems, especially large-scale and highly looped systems, it is still very difficult to define the optimal boundary of DMAs considering all the aspects of water distribution system management requirements. In this study, a DMA design methodology (or a DMA design model) was developed with Geographic Information Systems (GIS) and hydraulic distribution system model to determine the optimal DMA boundary.

본 연구에서는 공리적 설계 방법론에서 중요한 2가지 공리 중 독립공리를 시스템 개발에서 설계 기준으로 적용하였다. 기능 요구사항과 대응하는 설계 파라메터는 설계행렬을 구성하고 이를 이용하여 독립공리에 부합하는 설계 파라메터의 순서를 정한 후 블록 레벨링 시스템에서의 독립적 구성요소를 판별하였다. 이러한 공리적 설계의 결과로서 설계 순서에 맞는 블록 레벨링 시스템 구성을 도출하였다. 도출된 블록 레벨링 시스템 구성의 검증과 확인을 위해 블록 조립 현장에서 사용하고 있는 3차원 좌표 측정기인 토털 스테이션을 사용하여 실제 조립이 완료된 블록에 대하여 구현된 블록 레벨링 시스템을 적용하여 데이터를 비교하는 시험을 수행하였다. 토털 스테이션의 측정 데이터와 블록 레벨링 시스템의 수신 데이터를 비교하여 1 mm 이내의 정밀도로 블록 레벨링 시스템이 동작함을 검증하고 확인하였다.

본 연구에서는 파라매트릭 모델링 기법을 통해 다양한 대안을 고려할 수 있도록 개발된 StrAuto(이하 전산플랫폼)을 이용하여 감쇠장치에 따른 감쇠비 증가 효과와 풍하중 저감효과를 평가하였다. 비정형 초고층구조물의 수많은 구조시스템 대안선정을 지원하는 전산플랫폼은 설계자 또는 엔지니어에게 초기 대안을 결정하는데 있어 유용한 도구가 된다. 감쇠장치의 용량 및 추가 요구감쇠비의 크기를 산정하는 과정에서 중요한 원 구조물의 감쇠비에 대한 추정은 풍하중에 대한 실계측 자료를 기반으로 수행된 국내외 관련 연구의 결과를 사용하였다. 감쇠장치는 층간 설치형 수동형 감쇠장치와 질량형 능동형 감쇠장치 두 가지 유형을 고려하였다. 감쇠장치에 의해 추가되는 감쇠비는 FEMA에서 제안한 식을 이용하여 등가 정적 해석을 수행하여 산정하였다. 전산 플랫폼 내부에 감쇠장치의 용량을 최적화하는 알고리즘을 내장함으로써 최적의 감쇠장치 설계안을 자동적으로 도출할 수 있다. 감쇠장치 설치에 따른 물량저감 효과는 풍하중 저감계수로 평가될 수 있으며, 455m 높이의 초고층구조물을 대상으로 제안한 방법의 유효성을 검증하였다. 제안한 방법을 사용하여 비선형 시간이력 해석을 통해 얻어진 지붕층 변위와 층별 전단력을 근사적으로 추정할 수 있음을 확인하였다.

본 논문에서는 도로교 설계기준이 개편됨에 따라 변화된 활하중과 설계식의 검토를 하려한다. 이를 위해 강합성 플레이트 거더교와 PSC 거더교를 이용한 두 예제를 살펴본다. 기존 도로교설계기준 하중과 AASHTO LRFD 하중 그리고 새로 개편된 도로교설계기준 2015 한계상태설계법에 나온 하중을 적용하여 횡분배 계수법과 유한요소 격자해석을 통해 구한 포락선을 비교․검토한다. 또한 강합성 플레이트 거더교의 경우 중앙지간의 길이 변화에 대한 검토를 하고, PSC 거더교의 경우에는 가로보의 개수와 경간의 개수, 그리고 각 경간장의 변화를 주어 각각 그 차이점을 분석한다.

Recently, wind power has received attention as one of remarkable renewable energy resources, and worldwide researches about wind power are actively being proceeded. Wind turbine tower has a major role for safety in the wind turbine systems. It is necessary for design tower structure to consider various environmental conditions. Earthquake, as one of the such environmental loads, is ground motion that applied to bottom of the tower structure and has a possibility of critical effect to the wind tower structure. There are various ways for seismic analysis, but design specifications that are in use do not suggest detailed method for seismic analysis. In this study, seismic responses are analyzed through different ways and the adequacy of seismic design methods is examined.

This study documents the 3-phase BLDC(Brushless DC) motor to improve conventional ventilator motor. Energy efficiency, noise, and air pollution reduction for the high-performance vibration of the BLDC motor has been used in many fields. BLDC motors for ventilator, we studied the controller and software.

오늘날 대 산업분야는 과학 기술의 진보에 따라 비약적인 기술발달을 이루었다. 따 라서, 고객이 요구(Needs)하는 다양한 기능을 구현하기 위해 상당수 부분을 소프트웨 어 중심으로 달성하고 있다. 이렇듯, 과거의 하드웨어 중심의 자동차와 달리 소프트웨 어 중심의 기능 구현이 이행되고 있는 실정이다. 이렇다 보니, 시스템이 보다 복잡해 짐에 따라 시스템을 설계하고 제어하는데 있어서 상당한 어려움이 따르고 있다. 따라 서, 유럽에서는 자동차 분야의 전자제어 장비로 인한 기능안전을 달성하기 위해 ISO26262라는 국제표준을 제정하였다. 국제표준의 제정에 따라 국내 자동차 산업은 차량 시스템을 설계하는데 있어서의 노력, 뿐만 아니라, 기능안전이라는 안전부분을 대비해야하는 상황에 직면하게 되었다. 본 연구에서는 자동차 시스템의 상위 수준의 설계인 개념설계 단계에서 FMEA를 통한 안전성 활동 반영을 통한 하나의 단일화된 개발 방법론을 본 연구를 통해 제시하고자 한다. 따라서, 본 연구를 기반으로 향후 추가 연구를 수행한다면, 국내 자동차 산업, 뿐만 아니라, 대형복합 안전 중시 시스템 으로 확대하여 설계단계에서 안전성을 동시 고려한 시스템 설계 신뢰성 확보를 위해 도움이 될 것으로 기대 된다.

Recently, a lot of smart devices such as smart phones have been spread. The research on smart education based on the devices are being actively investigated. A typical example of them is EPub3.0 proposed by the IDPF. Even if the educational content has supported multimedia such as image, video, text to speech and etc, it does not support a 3D virtual content yet. So a virtual reality-based education has not been achieved. In this paper, we propose an educational content system in which a virtual education simulation is possible through smart devices. To do it, the proposed system consists of an authoring tool creating 3D virtual educational content, and a viewer visualizing the content. The experimental results showed possibility of virtual experience education.

The demand from customers on better products and systems seems to be ever increasing. To meet the demand, the systems are becoming more and more complicated in terms of both scale and functionality, thereby requiring enormous effort in the development. One bright spot of this trend is that such effort has been the driving forces of the remarkable advancement in modern systems development. On the other hand, safety issues appear to be critical in many large-scale systems such as transportation and weapon systems including high-speed trains, airplanes, ships, missiles/rockets launchers, and so on. Such systems turn out to be prone to a variety of faults and thus the resultant failure can cause disastrous accidents. For the reason, they can be referred to as safety-critical systems. The systems failure can be attributed to either random or systemic factors (or sometimes both). The objective of this paper is on how to reduce potential systemic failure in safety critical systems. To do so, a proper system design is pursued to minimize the risk of systemic failure. A focus is placed on the fact that complex systems have a lot of complicated interfaces among the system elements. To effectively handle the sources of hazards at the complicated interfaces and resultant failure, a method is developed by utilizing a design structure matrix. As a case study, the developed method is applied in the design of train control systems.

Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Light rail transit(LRT) with passenger capacity between bus and subway is driven by an unmanned control, so safety issues of LRT in emergency shall be considered more carefully than other rolling stock. Modern railway system is a complex system and many actions in emergency are required. In this view, interoperability approach is effective to identify the related elements in emergency. In this paper, we propose the method to generate the fire response scenario of unmann ed LRT based on the outputs of systems engineering architecture design methodology. The proposed method is could be contributed to establish more reliable and applicable fire response scenario.

The IGRINS is a near infrared high resolution spectrograph jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. We present design and fabrication of the optomechanical mount for the five mirrors, i.e., an input fold mirror, a slit mirror, a dichroic, and two camera fold mirrors. Based on the structure analysis and the thermal analysis of finite element methods, the optomechanical mount scheme satisfies the mechanical and the thermal design requirements given by the optical tolerance analysis. The performance of the fabricated mirror mounts has been verified through three IGRINS commissioning runs.

Control charts are generally used for process control, but the role of traditional control charts have been limited in case of a non-contaminated process. Traditional x-s control chart has not been activated well for such a problem because of trying to control processes as center line and control limits changed by the contaminated value. This paper suggests modified x-s control chart based on robust estimation. In this paper, we consider the trimmed mean of the sample means and the trimmed mean of the sample standard deviations. By comparing with ARL value, the responding results are decided. The comparison resultant results of traditional control chart and modified control chart are contrasted.

Recently, education game contents with advanced mobile and Web technology have been widely researched. However, considering of interaction involved for children, it is necessary user friendly interfaces and interesting interactions. In addition, it is important to design to encourage the user’s learning motivation as a way to the effect of educational game contents. Therefore, in this study, we designed and implemented the educational game contents system using inter-working between KINECT camera, PC, and android platform based humanoid robot. The designed system consisted of KINECT system for capturing hand gestures, game contents system for playing games, and android humanoid robot system for interacting with users. This system can lead to interests and willingness of users through handy interaction such as hand gestures and interesting quiz game contents. To improve effectiveness and userability, we plant to advance designed educational game contents system that can be operated on a smart TV system including a built-in camera as a further study.