• 호남수학학술지
• /
• 제37권1호
• /
• pp.7-27
• /
• 2015

Kuneth formula is to compute (co)-homology of $A{\otimes}B$ for known (co)-homology of the complexes A and B. In the ordinary case, this is done by using elementary homological methods in an abelian category. However, when we consider the bounded cochain complex with values in $\mathbb{R}$ and its structure as a real Banach space, the techniques of homological algebra for constructing K$\ddot{u}$nneth type formulas on it are not effective. The most notable facts are the image of a morphism of Banach spaces is not necessarily closed, and also the closed summand of a Banach space need not be a topological direct summand. The main goal of this paper is to construct the theory of K$\ddot{u}$nneth type formula on bounded cohomology with real coefficients in the suitable category of Banach spaces with some restricted conditions.

• 대한화학회지
• /
• 제6권1호
• /
• pp.29-31
• /
• 1962

電壓條件 永動時間 및 支持電解質溶液의 pH가 Al ion의 paper electrophoresis에 미치는 影響을 closed horizontal type의 泳動裝置를 써서 Michaelis buffer soln.으로 飽和시킨 paper strip에서 實驗的으로 檢討하였다. 그 結果 Al ion에 가장 適合한 pH, 電壓 및 泳動時間을 決定하였으며 pH=2.38에서 Al ion의 mobility는 $(1.004{\pm}0.0020){\times}10^{-4}\;cm^2\;sec^{-1}\;volt^{-1},\;Al(NO_3)_3\;soln.$의 isoelectric point는 pH=3.23 임을 알았다.

• Journal of Periodontal and Implant Science
• /
• 제28권2호
• /
• pp.371-376
• /
• 1998

This study presents an evaluation of the effectiveness of nonsurgical subgingival scaling and root planing related to initial pocket depth, type of teeth, and individual root surfaces. A total of 110 teeth designated for periodontal surgery in 67 patients with marginal periodontitis were selected and received thorough scaling and root planing with standard rigid Gracey curettes. After a healing period of 4 to 8 weeks, residual calculus was assessed at the time of periodontal surgery following the reflection of mucoperiosteal flap. The results demonstrated a high correlation between the percentage of residual calculus and initial pocket depth. It was further noted that tooth type and involved root surface also influenced the rate of calculus remnant. The results of this study suggest that complete removal of subgingival calculus utilizing conventional instrumentation via closed approach is rare.

• Structural Engineering and Mechanics
• /
• 제74권2호
• /
• pp.189-199
• /
• 2020

Researchers have elaborated several accurate methods to calculate member-end rotations or moments, directly, for bridge-type structures. Recently, the concept of rotation and moment propagation (RMP) has been presented considering bending flexibility, only. Through which, in spite of moment distribution method, all joints are free resulting in rotation and moment emit throughout the structure similar to wave motion. This paper proposes a new set of closed-form equations to calculate member-end rotation or moment, directly, comprising both shear and bending flexibility. Furthermore, the authors program the algorithm of Timoshenko beam theory cooperated with the finite element. Several numerical examples, conducted on the procedures, show that the method is superior in not only the dominant algorithm but also the preciseness of results.

• 한국실내디자인학회:학술대회논문집
• /
• 한국실내디자인학회 2008년도 춘계학술발표대회 논문집
• /
• pp.59-62
• /
• 2008

This research is to provide basic information for future development of an effective way for design office furniture. The purpose of this study is to provide foundation data that enable to design various office furniture. This article investigates what are the basic elements of office furniture and how various type of office furniture elements represent in many catalogues, articles. It was to understand what parts of office furniture elements influence when design the office furniture. Based on the research, conclusion was made as following: Through the 11 brands, it is found that rectangular-closed desk and tall closest is dominant in domestic brand whereas both open and closed desks are used in overseas brand and the closet design is changed based on the desk type.

• 한국정밀공학회지
• /
• 제22권6호
• /
• pp.98-108
• /
• 2005

Conventional robot manipulators actuated by motors with the speed reducer such as the harmonic drive have weakness in the load capacity, since the speed reducer does not have enough strength. To improve this, a new type of robot actuator based on the four-bar-link mechanism driven by the ball screw was constructed. Also, a new type of revolute robot manipulator composed of the developed actuators was developed. But, modelling errors occur due to the off-set from the nominal model since the exact modeling of the complex inertia variation of the four-bar-link actuator is very difficult. To control the proposed robot along the prescribed trajectory, a sliding mode control algorithm was applied with compensation function for the modeling errors. To show performance of the proposed controller, a computer simulation was performed, and its results was presented.

• 한국강구조학회 논문집
• /
• 제30권1호
• /
• pp.59-66
• /
• 2018

본 연구에서는 새로운 형태의 리브(${\Box}$형)를 갖는 보강판의 좌굴거동에 대한 매개변수 해석을 수행하였다. ${\Box}$형 리브의 제원에 따른 좌굴능력의 변화가 일정한 양상을 나타냄에 따라 특정 좌굴하중을 갖는 ${\Box}$형 리브 단면을 구하는 시스템을 제안할 수 있었으며, 이 시스템을 실교량의 강바닥판에 적용하였을 때 기존 폐단면 리브보다 더 경제적인 ${\Box}$형 리브 단면을 많이 얻을 수 있었다. 따라서 본 연구에서 제안한 ${\Box}$형 리브 시스템을 이용하면, 소요 좌굴 능력을 가지면서도 보다 경제적인 강바닥판 설계를 할 수 있을 것으로 판단된다.

• 한국추진공학회지
• /
• 제25권2호
• /
• pp.1-11
• /
• 2021

연소기 내부의 공동은 낮은 속도의 재순환영역과 유동의 진동을 일으켜 연료와 공기의 혼합 효율을 증대시키고, 화염을 유지함으로써 지속적인 연소를 가능하게 한다. 본 연구에서는 공동의 형상 인자에 따른 내부 유동의 특성을 실험과 2차원 전산해석을 통해 관찰하였다. 초음속 연소기 내 유동은 단순히 L/D 이외에도 다양한 공동 형상인자에 따라 크게 영향을 받는 것이 관찰되었다. 동일 L/D에서도 공동의 깊이에 따라 open과 closed 형태가 나타남을 확인하였고, 공동의 후방 경사각, 연소기 높이도 유동 특성이 달라지며, 이는 전압력 손실에 큰 영향을 미치는 것을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제27권2호
• /
• pp.238-245
• /
• 2003

To overcome the weakness in the load capacity of conventional robot manipulators actuated by motors with the speed reducer such as the harmonic driver, we proposed a new closed-chain type of the robot actuator which is composed of the four-bar-link mechanism driven by the ball screw. The robot manipulator is revolute-jointed and composed of four axes. The base axis is actuated by the lineal actuator such as the ball screw, and the others are actuated by the proposed actuator. We analyzed the mechanism of the actuators of the robot joints, and developed the dynamics model. The dynamics are expressed in the joint coordinates and then they are mapped into the sliding coordinates of the ball screw. We performed fundamental tests on the structure of the robot.

• 충청수학회지
• /
• 제33권2호
• /
• pp.271-285
• /
• 2020

In this paper, we have introduced a new type of covering property ${\beta}^t_{({\omega}_r,s)}$-closedness, stronger than $P^t_{({\omega}_r,s)}$-closedness [3] in terms of (r, s)-β-open sets [9] and β-ω_t-closures in bitopological spaces along with its several characterizations via filter bases and grills [15] and various properties. Further grill generalizations of ${\beta}^t_{({\omega}_r,s)}$-closedness (namely, ${\beta}^t_{({\omega}_r,s)}$-closedness modulo grill) and associated concepts have also been investigated.