• Journal of the Society of Naval Architects of Korea
• /
• v.50 no.5
• /
• pp.349-354
• /
• 2013

The blades of flexible propellers are formed by overlaying and adhering many layers of thin glass-fiber fabric sheets, are compressed and dried in the rigid mold. The current manufacturing process can not avoid the rather irregular deformation of the blades composed of non-isotropic non-uniform fabric structures, and inevitably introduces the different shape-forming errors between blades. In this paper, several flexible model propellers are precisely measured with three-dimensional optical instrument and compared with the original design geometry. The model propellers with the as-measured geometry are evaluated with the lifting-surface-theory-based propeller analysis code. The open-water performance are presented and discussed. The importance of the manufacturing accuracy is addressed to be able to apply the flexible propellers for propulsion of marine vehicles.

• Journal of Information Processing Systems
• /
• v.17 no.5
• /
• pp.918-932
• /
• 2021

Evaluation of the collaboration of the upstream and downstream enterprises in the manufacturing supply chain is important to improve their synergistic effect. From the supply chain perspective, this study establishes the evaluation model of the manufacturing enterprise collaboration on the basis of fuzzy entropy according to synergistic theory. Downstream enterprises carry out coordinated capital, business, and information flows as subsystems and research enterprises as composite systems. From the three subsystems, the collaboration evaluation index is selected as the order parameter. The compound fuzzy matter-element matrix is established by using its improved algorithm. Subordinate membership and standard deviation fuzzy matter-element matrixes are constructed. Index weight is determined using the entropy weight method. The closeness of each matter element is then calculated. Through a representative of the home appliance industry, namely, Gree Electric Appliances Inc. of Zhuhai, empirical analysis of data in 2011-2017 from the company and its upstream and downstream enterprise collaboration shows a good trend, but the coordinated development has not reached stability. Gree Electric Appliances Inc. of Zhuhai need to strengthen the synergy with upstream and downstream enterprises in terms of cash, business, and information flows to enhance competitiveness. Experimental results show that this method can provide precise suggestions for enterprises, improve the degree of collaboration, and accelerate the development and upgrading of the manufacturing industry.

• Current Optics and Photonics
• /
• v.4 no.1
• /
• pp.9-15
• /
• 2020

Fresnel zone plates have been widely used in many applications, such as x-ray telescopes, microfluorescence, and microimaging. To obtain an x-ray Fresnel zone plate, many fabrication methods, such as electron-beam etching, ion-beam etching and chemical etching, have been developed. Fresnel zone plates fabricated by these methods will inevitably lead to some nonideal factors, which have an impact on the focusing characteristics of the zone plate. In this paper, the influences of these nonideal factors on the focusing characteristics of the zone plate are studied systematically, by numerical simulations based on scalar diffraction theory. The influence of the thickness of a Fresnel zone plate on the absolute focusing efficiency is calculated for a given incident x-ray's wavelength. The diffraction efficiency and size of the focal spot are calculated for different incline angles of the groove. The simulations of zone plates without struts, with regular struts, and with random struts are carried out, to study the effects of struts on the focusing characteristics of a zone plate. When a Fresnel zone plate is used to focus an ultrashort x-ray pulse, the effect of zone-plate structure on the final pulse duration is also discussed.

• The Research Journal of the Costume Culture
• /
• v.14 no.1
• /
• pp.27-39
• /
• 2006

The field of textiles and clothing is intimately involved in the business as a practical study. Many researchers consider how apply the theory to the business. Therefore, the study explores a process which builds an efficient relationship of industry-university focused on the example applied to an industry-university project of uniform design. The development process of the studyis composed of 4 levels: research and analysis, design development, production of samples, and manufacturing. In the process of research and analysis, it found out preference of design elements. These elements were reflected in design development to satisfy employee of wearing uniform. In the level of design development, 20 designs were deployed to use CAD system. Five deigns of them were produced to samples in 3 stages. Finally, to manufacturing was in charge of cooperative enterprises with clothing production equipment and university played a role of inspector. From theses research results, it has known that the field of uniform business is suitable for industry-university project because an enterprise with an order can get advice about clothing, a manufacturing company is able to complement a weaknessin the design, and university can have a chance applied the theory to the business. After this, the study will make a contribution to setting the direction of business to industry-university project.

• The KIPS Transactions:PartD
• /
• v.16D no.4
• /
• pp.613-620
• /
• 2009

It is necessary to develop a system of judging whether or not the parts are defective easily at low cost, especially in a small scale factory which manufactures a large variety of products in small amounts. To develop such system, we require to recognize objects using human's cognitive ability under various circumstances. Human's high intelligence originates mostly from neocortex of human brain. The HTM theory, which is proposed by Jeff Hopkins, is one of the recent researches to model the operation principle of neocortex. In this paper we developed PRESM (Parts image REcognition System for small scale Manufacturing industry) system based on the HTM theory to judge badness of manufactured products. As a result of application to the real field of workplace environments we identified the superiority of our recognition system.

• Journal of Convergence for Information Technology
• /
• v.11 no.8
• /
• pp.8-13
• /
• 2021

The purpose of this study is to propose a throughput costing as a performance measurement tool to measure cost indicators, which are one of the indicators for evaluating organizational performance in a smart factory manufacturing environment. An empirical study by questionnaire was conducted, and 60 experts were surveyed to verify the hypothesis. As a result of the study, it was concluded that the information provided based on throughput costing is helpful in cost measurement and in evaluating organizational performance efficiency and effectiveness, and it was confirmed that this method has usefulness to support the planning and control process. It is proposed that the use of throughput costing by constraint theory, which can maximize throughput and optimize inventory levels in the manufacturing process, can find solutions to bottlenecks affecting the efficiency and effectiveness of organizational performance.

• Journal of Korea Society of Industrial Information Systems
• /
• v.29 no.3
• /
• pp.107-120
• /
• 2024

To study the relationship between various information sources and first-to-market product innovation, this research examined how the internal and external information sources relate to first-to-market product innovation and how government regulations (economic, social and administrative) affect first-to-market product innovations, applying the perspective of Institutional Theory. For the analysis, variables used were first-to-market product innovation, internal and external information sources, and economic, social, and administrative regulations. This study was conducted based on survey data from the Korean Innovation Survey 2020 by the Science and Technology Policy Institute of Korea (STEPI). The data analyzed included small and medium-sized enterprises (SMEs) in the manufacturing industry, and a total of 586 firms were used from 2017 to 2019. By analyzing the internal and external information source and government regulations that have been relatively underexplored in previous research, this study suggests new directions and provides practical and managerial implications based on the results.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.10 no.2
• /
• pp.27-39
• /
• 2000

Objectives : The purpose of this study is to analyze the factors associated with respirator usage on the basis of reasoned action theory. Methods : The data were collected from August 1 to September 30 1999, and study subjects consisted of 303 workers who were employed in the manufacturing industries. A self-administered questionnaire was used to measure the attitude, subjective norm and related factors. Results : In bivariate analysis, the variables related to protector usage were prevention of occupational disease, protection of toxic material, disturbance during working, troublesome of usage, proper exchange of protector. Multivariate logit analysis was used to estimate factors associated with respirator usage. Significant predictors that are related to respirator usage were attitude toward the behavior, size of industry and proper exchange of protector. Conclusions : The results suggest that it is strongly required to focus on attitude toward the behavior in order to improve workers' usage of respirator.

• Journal of the Korean Wood Science and Technology
• /
• v.15 no.2
• /
• pp.99-104
• /
• 1987

Fiber mats were made at various density levels, using fibers from papermill sludge, ricestraw and various mixtures of the two. The paper mill sludges were collected from Moorim Papermill Co, and Jeonjoo Papermill Co. They were soaked in the liquid sulfur compounds, sulfur-tall oil and sulfurpolyester compounds, and made into fiber-reinforced, sulfur-based composition board. Under optimum conditions of fiber mat preparation and saturation with molten sulfur and modified sulfur, the Young's moduls of the manufactured tiber-reinforced composition board are superior to those of conventional wood-based composition boards. For example, the moduli of elasticity of the composition board made from papermill sludge, with a density of 0.40gm/$cm^3$, were greater than 1,400,000psi as compared 800,000psi for high density hardboard(1.28gm/$cm^3$). The modulus of rupture of the best reinforced composition board manufactured was over 9000psi, comparable to 6000psi of high density hardboard. The proposed Bryant and Lee's theory, "Modified Rule of Mixtures" can be applicable to the nonoriented and short fibrous composition board, when it was modified from "Rule of Mixtures" established by Paul an Jones, and supplemented by Smith and Cox's theory, In the Bryant and Lee's theory of $E_c=\frac{1}{3}aE_fV_f+bE_mV_m$, the constants "a" and "b" for the composition boards made from papermill sludge and the mixtures of ricestraw and the sludge were identified to be in the ranges of 3.29~3.54 and -2.47~-2.80 respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.5
• /
• pp.13-18
• /
• 2017

In this work the augmented safety of Type 4 composite vessel in accordance with uniform-stress design has been demonstrated through a series of burst tests and structural analyses. For this end, three sample vessels were used: (1) designed as guided by the isotensoid dome theory (called iso-dome cylinder); (2) with dome longer compared to uniform-stress design (called prolate cylinder); and (3) with dome wider than uniform-stress design (called oblate cylinder). Structural analyses have been performed using ABAQUS finite element code based on the periodic symmetry to circumferential direction. As a result, the maximum stresses are induced around the bodies of all three cylinders. However, the analyses, with the assumption of possible defect demonstrate that the maximum stresses are induced around the dome knuckles for the prolate and the oblate cylinders. The results of the burst tests for the three cylinders show that the burst initiates from the cylinder body of the iso-dome cylinder and from the dome knuckles of the prolate and the oblate cylinders. Finally, it is recommended that, to comply with DOT CFFC 2007, the dome shape should be designed and fabricated as guided by the isotensoid dome theory.