• 공업화학
• /
• 제8권3호
• /
• pp.410-415
• /
• 1997

Fibrious potassium hexatitanate whisker was produced from the calcination process using a mixture of the natural rutile ore and industrial $K_2CO_3$. Fibrous Potassium titanate was prepared by the following procedures the starting material consisting of $K_2O{\cdot}4.4TiO_2$ was calcined at $1050^{\circ}C$ for 3 hrs. The calcined products obtained under the above condition consisted mainly of potassium hexatitanate with a small admixture of potassium dititanate and potassium tetratitanate. Therefore the single phase of potassium hexatitanate was obtained by heat treatment of $850^{\circ}C$, 3 hrs.

• 산업경영시스템학회지
• /
• 제38권4호
• /
• pp.109-116
• /
• 2015

This paper is concerned with the single vendor single buyer integrated production inventory problem. To make this problem more practical, space restriction and lead time proportional to lot size are considered. Since the space for the inventory is limited in most practical inventory system, the space restriction for the inventory of a vendor and a buyer is considered. As product's quantity to be manufactured by the vendor is increased, the lead time for the order is usually increased. Therefore, lead time for the product is proportional to the order quantity by the buyer. Demand is assumed to be stochastic and the continuous review inventory policy is used by the buyer. If the buyer places an order, then the vendor will start to manufacture products and the products will be transferred to the buyer with equal shipments many times. The mathematical formulation with space restriction for the inventory of a vendor and a buyer is suggested in this paper. This problem is constrained nonlinear integer programming problem. Order quantity, reorder points for the buyer, and the number of shipments are required to be determined. A Lagrangian relaxation approach, a popular solution method for constrained problem, is developed to find lower bound of this problem. Since a Lagrangian relaxation approach cannot guarantee the feasible solution, the solution method based on the Lagrangian relaxation approach is proposed to provide with a good feasible solution. Total costs by the proposed method are pretty close to those by the Lagrangian relaxation approach. Sensitivity analysis for space restriction for the vendor and the buyer is done to figure out the relationships between parameters.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권3호
• /
• pp.1-6
• /
• 2015

The rapid industrial development is facing problem due to energy depletion in Korea. So that, it can be necessary to develop alternative energy sources. Alternative energy like biofuels can be produced by using waste fuel, which is ecofriendly. As we know, the organic waste was banned to dump in landfill and ocean dumping. The most practicable method usually used to reduce organic waste is getting feedstuff or composting, considering the discharge characteristics of agricultural by-products waste treatment were selected. In this study, bio-coal was made using agriculture by product. Biocoal was prepared by adding 50 g of uniformly mixture into reactor and was carbonized at low temperatures 210, 220, and 230℃. The time of reaction was 1, 2 and 3 hours. Bio-coal approximately was similar to the standard of solid fuels. Other characteristics of fuel were also studied. The experiments which were analyzed were moisture content and calorific value, ash, chlorine, sulfur and heavy metals analysis as mercury, cadmium, lead, arsenic, and chromium. As a result, bio-coal 220℃, 2 hours was the optimal conditions while heating.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제39권1호
• /
• pp.34-38
• /
• 2019

In this study, we investigated the effect of silkworm, and its by-products on exercise endurance, muscle mass, and fatigue recovery using ICR mice model. Powders of silkworm, pupae, dongchunghacho, and silk powder were suspended in water and feed to mice for 2 weeks. The forced swimming time was increased by 4.3, 4.1 and 2.8 seconds after silkworm, pupae, and dongchughacho administration compared to DW fed group. Increases in exercise ability were achieved by difference mechanism according to feeding materials. Pupae increased muscle mass by 129% compared with the control group which may effect on elongation of swimming time. Dongchunghacho improved the plasma concentrations of fatigue markers such as creatinine, blood urea nitrogen (BUN), and D-lactate. Silkworm administration showed dual effect, the muscle mass induction (114% vs. control) and anti-fatigue (plasma creatinine, BUN, and D-lactate were 63, 75, and 78% vs. con) effect which contributed most elongated swimming time. In conclusion, silkworm and its by-products including pupae and dongchunghacho with the predominant protein and bioactive components improved muscle mass and showed anti-fatigue effect which could promote exercise performance ability.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1999년도 제29회 춘계학술대회
• /
• pp.80-85
• /
• 1999

Residual stress in the forged products directly affects material stability, resistance to deformation, accuracy, and fatigue life of products. It is very important to study the residual stress distributions in forged products and to monitor operating conditions for the minimum tensile or maximum compressive residual stresses. As a way to study the residual stress formation due to radial forging, a three dimensional theoretical model was developed using ANSYS finite element program. Using the developed model, residual stress distributions in forged product were calculated and selected results were compared with the published experimental data to verify the effectiveness of the developed model.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2001년도 추계학술대회 논문집
• /
• pp.313-318
• /
• 2001

Compression molding is widely used process for the industrial forming of fiber reinforced plastic articles. Its applications are of an extreme variety and the products range from large parts, such as used in the automotive industry to much smaller objects. In this paper, distribution of fiber orientation by the image processing method for rib type compression molded products of each fiber content is measured. And the effects of fiber content, product size on the orientation state are discussed.

• Journal of Mechanical Science and Technology
• /
• 제18권12호
• /
• pp.2137-2147
• /
• 2004

The recycling cell formation problem means that disposal products are classified into recycling part families using group technology in their end-of-life phase. Disposal products have the uncertainties of product status by usage influences during product use phase, and recycling cells are formed design, process and usage attributes. In order to deal with the uncertainties, fuzzy set theory and fuzzy logic-based neural network model are applied to recycling cell formation problem for disposal products. Fuzzy C-mean algorithm and a heuristic approach based on fuzzy ART neural network is suggested. Especially, the modified Fuzzy ART neural network is shown that it has a good clustering results and gives an extension for systematically generating alternative solutions in the recycling cell formation problem. Disposal refrigerators are shown as examples.

• 대한기계학회논문집A
• /
• 제26권1호
• /
• pp.83-94
• /
• 2002

Analysis technology is widely accepted and quite popular these days. Incorporation of the analysis result into design process is a key factor for the success of the analysis area. A few design software products have been commercialized. Generally, they are trying to make an interface between various design methods and analysis software. Optimization is a representative design method. The products are investigated and compared for the aspects of user convenience and algorithm performance. A few popular products are selected. Graphic user interface (GU) is compared for the function and efficiency. The performances of the optimization algorithms are tested by mathematical and engineering examples. The results are discussed.

• 디자인학연구
• /
• 제13권
• /
• pp.27-42
• /
• 1996

With the rapid development of nowadays technologies, the environment of product development is experiencing structural changes than ever. Manufacturers are put under never-experienced pressures to launch their products in the market both faster and less expensively than their competitors while continuously improving product quality These pressures have given birth to so-called, Concurrent Engineering which is a systematic approach to the integrated, concurrent design of products and their related processes, including manufacture and support. Most manufactiring companies now recognize the importance of concurrent engineering and put heavy emphasis on the research and impementation of concurrent engineering. However, with this fundamental change in the process of product development, designers rarely pay attention to this newly demanding process. Designers still stay in the middle of process, satisfying their roles in dealing with aesthetic points of product. Designers badly need to incorporate the concept of concurrent engineering to design to design process and to adapt to this new environment. With these backgrounds, the study sets the objective to understand the nature of concurrent engineering and explore the possibility of it's application to industrial design. Particularly this study focuses on how the concept of concurrent engineering can be applied from the stage of form development to prototyping. At first, background, objectives, and scope of the study are discussed as an introductory part. It is followed by reviewing theories of concurrent engineering such as definition, history, technologies, examples, state of art and so on. Subsequently industrial design is viewed in terms of concurrent engineering and problems in industrial design are identified. Base on the findinss of precedent part of study, new process of industrial design incorporating concurrent engineering is developed. For the demonstration of new process, a case study of design of palm-top printer is introduced. Case study shows how the sketch, and forms can be transformed into prototyping with the simultaneous cooperation with engineering and other related specialists. Finally the study in summarized and future studies are prospected.

• Journal of Computational Design and Engineering
• /
• 제2권3호
• /
• pp.157-164
• /
• 2015

This paper discusses an optimization-based approach for the design of a product platform for industrial three-axis linear-type robots, which are widely used for handling objects in manufacturing lines. Since the operational specifications of these robots, such as operation speed, working distance and orientation, weight and shape of loads, etc., will vary for different applications, robotic system vendors must provide various types of robots efficiently and effectively to meet a range of market needs. A promising step toward this goal is the concept of a product platform, in which several key elements are commonly used across a series of products, which can then be customized for individual requirements. However the design of a product platform is more complicated than that of each product, due to the need to optimize the design across many products. This paper proposes an optimization-based fundamental framework toward the design of a product platform for industrial three-axis linear-type robots; this framework allows the solution of a complicated design problem and builds an optimal design method of fundamental features of robot frames that are commonly used for a wide range of robots. In this formulation, some key performance metrics of the robot are estimated by a reducedorder model which is configured with beam theory. A multi-objective optimization problem is formulated to represent the trade-offs among key design parameters using a weighted-sum form for a single product. This formulation is integrated into a mini-max type optimization problem across a series of robots as an optimal design formulation for the product platform. Some case studies of optimal platform design for industrial three-axis linear-type robots are presented to demonstrate the applications of a genetic algorithm to such mathematical models.