• KIEAE Journal
• /
• 제7권6호
• /
• pp.107-112
• /
• 2007

Recently hybrid beam system is widely used because it has many structural advantages such as short construction period and low story height etc. Generally steel wide flange beam exposure type and embedded type hybrid beams are constructed. Even though exposure hybrid beam is easily constructed, the fire proofing protection process is necessary because steel wide flange beam cannot resist to fire itself. Story height reduction type hybrid beam, which is introduced hybrid beam in this paper, does not need fire proofing protection process because it is constructed as a fully embedded type hybrid beam. Developed construction process and actual construction cases of story height reduction type hybrid beam were introduced in this study.

• 한국기계기술학회지
• /
• 제20권6호
• /
• pp.886-893
• /
• 2018

In this study, clinching characteristics of aluminum and galvanized steels were investigated for the application of clinching as a joining technique to aluminum wheelhouse assembly. A6451 aluminium alloy and galvanized steel sheets were joined by hybrid joining(clinching + adhesive bonding). Tensile-shear load and fracture mode of hybrid joints were investigated. Maximum tensile-shear load of hybrid joints was about six times higher than that of clinched joints without adhesive. Energy absorption values of hybrid joints were higher than those of clinched joints without adhesive as well as resistance spot welded steel joints. Developed aluminum wheelhouse assembly showed higher static stiffness than the existing steel parts. Aluminum wheelhouse inner panel unit was 44% lighter than the steel unit, and the final assembled aluminum wheelhouse was 14.6% lighter than the existing steel parts.

• 한국초전도ㆍ저온공학회논문지
• /
• 제3권1호
• /
• pp.22-28
• /
• 2001

A vortical axis flywheel system was conceptualized, which uses a hybrid superconductor bearing set to carry the wheel part load. The multiple designs of magnetic bearing and superconductor bearing were analyzed by using conventional numerical magnetostatic analysis method The best medels were selected among four different types of Permanent magnet bearings for upper bearing and two types of superconductor bearing for lower bearing, respectively These results were discussed in regard of application to the flywheel system with a Passive hybrid magnetic bearing set.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
• /
• pp.566-569
• /
• 1987

The primary difficulties encountered in the use of step motors are underdamped response when stopping at a specified position and dynamic instability during high-speed slewing. This paper proposes a speed and position detection scheme using the back EMF generated by the rotating permanent magnet field of a two-phase 1.8.deg. hybrid step motor, and presents its application to the state-variable feedback control of the hybrid step motor. All simulation results in a single step response show that the hybrid step motor performances such as peak overshoot and settling time are greatly improved.

• Restorative Dentistry and Endodontics
• /
• 제45권2호
• /
• pp.13.1-13.10
• /
• 2020

Objective: The aim of this study was to evaluate the influence of different modeling agents on the surface microhardness (Vickers hardness number; VHN), roughness (Ra), and color change (ΔE) of a nano-hybrid composite with or without exposure to discoloration by coffee. Materials and Methods: Sixty-four cylinder-shaped nano-hybrid composite specimens were prepared using a Teflon mold. The specimens' surfaces were prepared according to the following groups: group 1, no modeling agent; group 2, Modeling Liquid; group 3, a universal adhesive (G-Premio Bond); and group 4, the first step of a 2-step self-adhesive system (OptiBond XTR). Specimens were randomly allocated into 2 groups (n = 8) according to the storage medium (distilled water or coffee). VHN, Ra, and ΔE were measured at 24 hours, 1 week, and 6 weeks. The Kruskal-Wallis test followed by the Bonferroni correction for pairwise comparisons was used for statistical analysis (α = 0.05). Results: Storage time did not influence the VHN of the nano-hybrid composite in any group (p > 0.05). OptiBond XTR Primer application affected the VHN negatively in all investigated storage medium and time conditions (p < 0.05). Modeling Liquid application yielded improved Ra values for the specimens stored in coffee at each time point (p < 0.05). Modeling Liquid application was associated with the lowest ΔE values in all investigated storage medium and time conditions (p < 0.05). Conclusion: Different types of modeling agents could affect the surface properties and discoloration of nano-hybrid composites.

• Coupled systems mechanics
• /
• 제9권2호
• /
• pp.147-161
• /
• 2020

Constructive merging of "basic" systems of different behavior creates hybrid systems. In doing so, the structural elements are grouped according to the behavior in carrying the load into a geometric order that provides sufficient load and structure functionality and optimization of the material consumption. Applicable in all materializations and logical geometric forms is a transparent system suitable for the optimization of load-bearing structures. Research by individual authors gave insight into suitable system constellations from the aspect of load capacity and the approximatemethod of estimating the participation of partialstiffnesswithin the rigidity ofthe hybrid system. The obtained terms will continue to be the basisfor our own research of the influence of variable parameters on the behavior of hybrid systemsformed of glued laminated girder and cable of different geometric shapes. Previous research has shown that by applying the strut-type hybrid systems can increase the load capacity and reduce the deformability ofthe free girder.The implemented parametric analysis pointsto the basic parameterin the behavior of these systems-the rigidity ofindividual elements and the overallstiffnessofthe system.The basic idea ofpre-stressing is that, in the load system or individual load-bearing element, prior to application of the exploitation load, artificially challenge the forcesthatshould optimize the finalsystembehaviorin the overall load. Pre-stressing is possible only if the supporting system orsystem's element possesssufficientstrength orstiffness, orreaction to the imposed forces of pre-stressing. In this paper will be presented own research of the relationship of partial stiffness of strut-type hybrid systemsofdifferentgeometric forms.Conducted parametric analysisofhybridsystemswithandwithoutpre-stressing, and on the example of the glulam-steel strut-type hybrid system under realistic conditions of change in the moisture content ofthe wooden girder,resulted in accurate expressions and diagramssuitable for application in practice.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
• /
• 제4권9호
• /
• pp.283-288
• /
• 2015

하이브리드 클라우드 컴퓨팅 환경에서 많은 과학자들이 과학 응용을 수행하고 있으나, 클라우드 컴퓨팅 서비스를 제공하는 각 회사들의 자원 표기법이 상이하고 복잡하여 사용에 어려움이 따르고, 응용에 적합한 클라우드 자원을 선택하는 것이 어렵다. 클라우드 서비스 간에 상호 호환성을 제공해주는 하이브리드 클라우드 환경에서의 표준화된 자원 명세 표기법이 필요하다. 과학자들은 기존에 자신들이 수행했던 자원이나 가장 좋은 성능의 자원에서만 수행하려는 경향이 있어, 비용, 시간을 효율적으로 수행하면서 응용에 적합하고, 기존의 실험과 유사하게 진행할 수 있는 자원을 추천해주는 서비스가 필요하다. 하이브리드 클라우드 서비스의 표준화를 위해 인터클라우드 프로젝트가 진행되고 있으나, 과학 응용 실험에 적합한 자원의 선택을 위해 필요한 클라우드 자원의 특성들을 나타내는 데 한계가 있다. 본 논문에서는 하이브리드 클라우드 환경에서 시맨틱 클라우드 자원 서비스를 제안한다. 통계 기법으로 과학 응용의 특징에 따라 응용에 적합한 클라우드 자원을 그룹으로 분류하고 분류된 유사한 클라우드 자원 그룹을 가지고 시맨틱 클라우드 자원 추천 서비스 기법을 제공한다. 제안한 알고리즘을 통해 시맨틱 클라우드 추천 서비스 기법을 제공하면, 효율적인 자원의 가용성과 비용으로 응용을 수행할 수 있고, 응용에 적합한 클라우드 자원을 추천할 수 있다.

• Journal of Welding and Joining
• /
• 제33권2호
• /
• pp.85-90
• /
• 2015

Recently many studies for improvement of productivity and automation of process are in progress, and among others, laser-arc hybrid welding that combined laser and arc has attracted much attention. Since parameters by interactions as well as the parameters of each heat source should be considered, There are a lot of hardship in actual application, even though many researches have been done so far. Therefore in this study, bead welding was done to examine the effects of the flow rate of shield gas and the distance between laser and arc during laser-arc hybrid welding. As for hybrid heat source, disk laser and MIG were used. As experiment result, sound bead and weld with no defect were formed when the flow rate of front and rear shield gas were respectively 20 l/min and 15 l/min, and deep penetration was done at DLA=3 mm.

• 전력전자학회논문지
• /
• 제10권2호
• /
• pp.203-210
• /
• 2005

IMT2000과 같은 휴대용 무선통신 시스템을 위한 혼성마이크로 동력원에 대한 연구를 수행하였다. 혼성마이크로 동력원은 태양전지, 슈퍼커패시터, 리튬이온 전지로 이루어져 있다. 주기적인 펄스성 부하에 대응하기 위하여, 슈퍼 커패시터가 리튬이온 전지와 병렬로 연결되어 펄스전류를 흡수한다. 태양전지는 배터리에 전류를 공금하며, 최대전력점에서 동작하도록 제어된다. 펄스성 부하에도 적용될 수 있는 최대전력점 추적기법이 소개되며, 실험을 통해서 완벽한 추적성능을 입증하였다. 혼성마이크로 동력원들 간의 매칭을 위한 제어기 설계 기법이 제시되며, 실험을 통해 성능을 입증하였다.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2013년도 춘계학술대회
• /
• pp.749-750
• /
• 2013

스마트폰의 빠른 발전으로 인해 스마트폰 사용자가 늘어났고 어플리케이션의 서비스는 확대되어 서비스 이용자간의 커뮤니케이션들이 활성화 되고 있다. 이런 어플리케이션 중에서 학교 급식의 품질과 기대도를 알 수 있게 하는 서비스는 찾아 보기 힘들다. 또한 기존의 어플리케이션은 특정 디바이스에서만 동작하여 디바이스의 호환이 어렵다. 따라서 HTML5을 기반으로 하는 하이브리드 앱을 개발하였고 이 어플리케이션을 통해 학교의 급식을 학생들에 의해 모니터링 될 수 있고 하나의 커뮤니케이션을 형성할 수 있다.