• Journal of applied mathematics & informatics
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• 제26권3_4호
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• pp.793-809
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• 2008

The aim of this article is focused on providing numerical solutions for system of second order robot arm problem using the RK-eight stage seventh order limiting formulas. The parameters governing the arm model of a robot control problem have also been discussed through RK-eight stage seventh order limiting algorithm. The precised solution of the system of equations representing the arm model of a robot has been compared with the corresponding approximate solutions at different time intervals. Results and comparison show the efficiency of the numerical integration algorithm based on the absolute error between the exact and approximate solutions. Based on the numerical results a thorough comparison is carried out between the numerical algorithms.

• Food Science and Biotechnology
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• 제18권4호
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• pp.910-916
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• 2009

Present work was focused on the influence of methylcellulose (MC) on steady rheology of wheat gliadin solution and the properties of glycerol plasticized gliadin films. The presence of MC below 0.99 wt% improved viscosity and flow activation energy of the 10 wt% gliadin solution significantly. In the casting films containing 0.2 g glycerol/g dry protein, the MC component aggregated in the gliadin matrix. The blend films containing less than 7.7 wt% MC exhibited higher Young's modulus (E) and tensile strength (${\sigma}_b$) and lower elongation at break (${\epsilon}_b$) in comparison with the pure gliadin film, which was related to the intermolecular interaction between MC and gliadins, the brittle fracture of the aggregated MC component, and the increase in glass transition temperature ($T_g$) of the gliadin phase. Increasing MC content led to a slight increase in water vapor permeability (WVP) without significant influence on the moisture absorption (MA).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.20-23
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• 1994

It is well known that the Boyd's theorem states the relation between the imaginary eigenvalues of discriminant H of Riccati equation (A, R, Q) and the singular value of transfer function, but it is only available for R .geq. 0 and Q .geq. 0. In this paper, we extend Boyd's theorem for two case, that is, R is symmetric, Q is sign definite, and R is sign definite, Q is symmetric. We give under the condition that there is a real symmetric solution of Riccati equation the relation between H has imaginary eigenvalue and the maximum eigenvalue of transfer functoin. Finally, we give a necessary and sufficient condition to determine whether H has imaginary eigenvalue under some conditions.

• KIEAE Journal
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• 제14권6호
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• pp.15-21
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• 2014

Recently, energy generation using algae technology is being promising due to the emerging issues on energy insufficiency and environmental contamination, although the solution has not been resolved in aspect of technological and economical efficiencies since it was originally proposed in the early 1980s by many scholars. The energy production technology using algae materials has great values as not only a solution for new energy generation but also an eco-friendly sustainable building equipment system. In addition, cultivation tank for algae using water sources seems to play a role as a decreasing system for thermal transmittance on building components. This study aims at investigating the adaptability towards the future sustainable building with algae technology and testifying the energy efficiency of the algae skins by operating a couple of simulation tools to measure building performances for the proposed prototype of the façade system.

• 대한화학회지
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• 제17권3호
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• pp.213-223
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• 1973

透析液 및 溶媒液의 攪拌이 透膜面에 미치는 流體力學的인 壓力分布狀態를 究明하였고, 攪拌으로 招來되는 透膜面兩面의 壓力不均衡을 除去할 目的으로 攪拌裝置의 開發을 試圖하였다. 다음 攪拌速度가 透析係數에 미치는 影響을 究明하여 가장 正確한 透析係數를 求할 수 있는 攪拌速度를 確定시켰다.

• 센서학회지
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• 제24권1호
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• pp.35-40
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• 2015

Electrospinning method has easy preparation of nanofibers with a simple and versatile technique. Electrospun nanofiber is widely used by the simple approach and have great potentials in the numerous applicaitons of medicine, photonics, catalysts, sensors, etc. including advantage of their specific characteristics such as large surface to volume ratio. This paper focused on the fabrication of cobalt electrospun nanofibrer for applications such as electronic, optical and mechanical devices by metal based material. We fabricated cobalt nanofibers on aluminum foil by an electrospinning method. The electrospinning process was performed at a high voltage, 8 kV. The distance between the needle tip and the solution surface in the bath was 5 cm. The PVB - cobalt based nitrate solution was filled in a 10 mL syringe connected to a 22 gauge needle. We confirmed electrospun cobalt nanofiber after annealing process by SIMS (Secondary Ion Mass Spectrometry) analysis. The concept design, fabrication and results of mapping measurements are reported.

• 품질경영학회지
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• 제18권1호
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• pp.65-76
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• 1990

A lot-sizing model for multi-stage MRP systems is proposed, in which known demands must be satisfied. In this model, an approach with considerations of initial inventory and limited production capacity is involved. Most of the studies on the lot-sizing techniques for multi-stage material requirement planning systems have been focused upon two basic approaches. One approach is to develope an algorithm yielding an optimal solution. Due to the computational complexity and sensitivity of the optimal solution to the problem of lot sizing, heuristic approaches are often employed. In this paper, the heuristic approach is used by sequential application of a single-stage algorithm with a set of modified cost by the concept of multi-echelon costs. The proposed method is compared with an lot-sizing method(Florian-Klein Model) to prove its effectiveness by numerical examples.

• 한국수학교육학회지시리즈A:수학교육
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• 제46권1호
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• pp.69-79
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• 2007

Students experience many problem solving activities in school mathematics. These activities have focused on finding the solution whose existence was known, and then again conjecture about existence of solution or posing of problems has been neglected. It needs to put more emphasis on conjecture and problem posing activities in school mathematics. To do this, a model and examples of designing mathematical activities centered on conjecture and problem posing are needed. In this article, we introduce some examples of designing such activities (from the pythagorean theorem, the determination condition of triangle, and existing solved-problems in textbook) and examine suggestions for mathematics education. Our examples can be used as instructional materials for mathematically able students at middle school.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.445-450
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• 2004

Due to rapid development of If, difference types of services and platforms are being developed increasingly. With the emerging mobile technologies, Geographic Information System (GIS) is also getting more attention recently. But it is known to have some limitations in being served in different types of mobile devices and platforms. While information services are limited by data format and data exchange between platforms, the extensible Markup Language (XML) is getting focused as the most promising technology as the solution to such problem. Geographic Markup Language (GML) is based on XML technology and is being frequently mentioned recently as the solution to service problem on different mobile devices as well as the internet. In this study, we suggested the framework to use the GML in order to transfer and represent geographical data through the on-line or wireless platforms. We compared different application types which are currently used with GML and proposed to improve GIS services using the GML in geographical data transfer and description.

• Corrosion Science and Technology
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• 제7권3호
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• pp.173-178
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• 2008

Recently an electrochemical noise method (ENM) with three electrodes has gained attention as a corrosion monitoring system in chemical plants. So far a few studies have been carried out for localized corrosion and environmental cracking of chemical plant materials. In this paper the ENM system is briefly summarized. Then an application of ENM to general corrosion for chemical plant materials is described. The emphasis is focused upon the analysis of stress on the corrosion cracking process of austenitic stainless steel in 30% $MgCl_2$ aqueous solution and the corrosion fatigue crack initiation process of 12 Cr stainless steel in 3% NaCl aqueous solution by ENM. Finally future problems for ENM to monitor regarding corrosion and environmental cracking in chemical plants are discussed.