• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.52-57
• /
• 2001

In this paper, the optimum designs of air-bearing surface(ABS) are achieved effectively by using reduced basis concept which can reduce the number of design variables although the design space is distended. Generally, the optimization method is more effective than the trial and error. However, the efficiency of the former is largely dependent on the number of the design variables. In order to reduce the number of design variables and increase the efficiency, reduced basis concept is applied. We can define the desired design as a linear combination of basis designs using this concept. From this optimization method with reduced basis concept, we easily obtain the optimum designs of ABS whose target flying heights are 25, 20, 15 nm.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.3
• /
• pp.343-348
• /
• 2003

In this study, optimum designs of the air-bearing surface (ABS) are achieved using the reduced basis concept which can effectively reduce the number of design variables without cutting down on the design space. Even though the optimization method is easier and more applicable to handle than the trial-and-error method, its efficiency is largely dependent on the number of the design variables. Hence, the reduced basis concept is applied, by which the desired design can be defined as a linear combination of basis designs. The simulation results show the effectiveness of the proposed approach by obtaining the optimum solutions of the sliders whose target flying heights are 25, 20, and 15nm.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.15 no.1
• /
• pp.12-18
• /
• 1978

From the state table of sequential machines, Roomers) obtained minimal k co-mapping chain(k-CC) and proposed an algorithm obtaining binary partitions which were seed partitions of S-shift registers. By comparing and processing bits simply, this paper obtained two different algorithms more efficient than that of Roome's for obtaining such binary partitions and defined the concept of the triple pair of the basis partitions. By using the concept, given set of basis partitions was reduced to the set containing elements of the triple pair only and the algorithm became quite simple.

• Korean Security Journal
• /
• no.50
• /
• pp.287-303
• /
• 2017

Industrial security research has shown a rapid increase over the past decade. With the establishment of the Korean Association for Industrial Security in 2008 and the establishment of the departments of industrial security in recent years, academic interests and research on industrial security are also spreading at a rapid pace. Although academic interest and research have grown in quantitative terms, research on theoretical fields that are the basis of academic systematization is extremely limited. There is a focus on the issue of specific issues and practical solutions without worrying about the theoretical basis including conceptualization. Therefore, in most studies, the concept of industrial security remains at the level of accepting the concept applied in the previous research. Most industrial security research focuses on the specific topic of 'industrial technology protection' because it considers the concept of industrial security to be reduced to industrial technology protection. Although industrial security is composed of a wide range of fields, recognizing a specific field as an entirety of industrial security appears to be a serious problem. As a result, the concept of industrial security in industrial security research is being used ambiguously, incorrectly, and conveniently. It is necessary to accurately and recognize the concept of industrial security based on logical clarity and empirical feasibility.

• Journal of Korean Elementary Science Education
• /
• v.35 no.3
• /
• pp.377-387
• /
• 2016

Whether textbooks faithfully reflect the curriculum contents is an important educational issue. The previous studies on the textbooks did not analyze the relationship described in the textbooks or the structure. In this regard, this study aims to analyze how the concept of life science area in the elementary school science textbooks developed on the basis of the 2009 revised curriculum is linked. In addition, it seeks to analyze how the concept presented in the learning content achievement standards of the curriculum is connected to other concepts. Towards this end, the conceptual linkage of eight units in the life science domain of elementary school science textbooks based on the 2009 revised curriculum was analyzed. The contents of the life science domain in the science textbooks were analyzed through a semantic network analysis, and the semantic network on the concept linked to the one described in curriculum's learning objectives was also analyzed. The results are as follows: 1) It will be difficult for students to understand the concept due to the complexity of the semantic network resulting from a number of concepts. 2) The curriculum's learning objectives presented in the curriculum are not faithfully reflected in the textbooks. 3) The textbooks are described on the basis of specific curriculum's learning objectives. Based on the findings of this study, the number of concepts described in the elementary school science textbooks needs to be significantly reduced so that the concepts can be meaningfully linked to each other.

• 사회경제평론
• /
• v.31 no.3
• /
• pp.165-201
• /
• 2018

According to F. Nietzsche and A. N. Whitehead, the fatal error of the modern Western ontology is to mistakenly assume that the structure of reality is the same as the structure of language, and to misplace the fictional linguistic subject as a realistic subject. This fictional concept of the subject is the concept of person. This paper will analyze how this fictional concept of person forms the basis for the development of modern finance. The historical period and place of analysis of the paper is England in the late 17th century. At this time and place, the modern form of banking began, and the concept of person was developed philosophically by English intellectuals, especially by John Locke. And at the same time, joint-stock companies and the English nation state acquired their independent abstract personhood. The fictional concept of person has reduced social relations to "exclusive property rights" and "creditor-debtor relations," and this reduction forms the ontological basis of modern finance. In modern finance where property rights and creditors' rights are mixed, property owners excercise exclusive property rights but avoid responsibility for the exercise by being transformed to creditors. Furthermore, property owners' privilege were extended when the modern groups-joint-stock companies and the nation state-who are endowed with eternal and independent personhood are reduced to debtors for the property owners.

• Tribology and Lubricants
• /
• v.4 no.1
• /
• pp.43-55
• /
• 1988

A Study on the effect of the additives in lubricating oil was investigated on the basis of the thermal activated wear theory in terms of their wear behaviours, using four ballwear machine. The sample oils, which included diethyl-3, 5-di-t-butyi-4-hydroxy-benzyl phosphonate (DEP), ZDDP and TCP additives respectively, showed distinct wear characteristics depending upon the bulk oil temperature and the sliding velocity. The newly synthesized additive, viz., DEP showed excellent antiwear performance cornpared with the conventional additives, ZDDP and TCP. On the basis of the experimental results, it is reduced that the wear mechanism of the conventional additives, viz., ZDDP and TCP is the protective film formation and their antiwear capability is depending upon the shearing strength of the film formed. On the other hand, the new additive, DEP showed that the secondary activation energy was much eliminated and so, the thermal instability was reduced by the hydrogen scavenging reaction of the new additive, which was virtually an endothermic reaction process.In conclusion, a new concept of antiwear mechanism is estabilished and testified. And new chemical, which showed the function of hydrogen and free radical scavenging role, is synthesized and introduced as the new, highly antiwear effective lubricating oil additive.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.12 no.2
• /
• pp.43-50
• /
• 2024

Purpose: The present study investigates if the type of organizational culture influences the level of job-related stress. This study is significant because creating the need to explore the concept to become more informed on the best practices to promote and foster a positive culture that prioritizes workers, it could result in a healthier workforce, improved organizational performance, and success. Research design, data and methodology: Examining previous studies by other researchers was the primary research tool for this study. The organized approach of gathering data and assessing related work was vital in developing a fundamental basis for advancing knowledge on this concept while enhancing theory development and drawing more informed conclusion. Results: These four types, including the clan, adhocracy, hierarchical, and market cultures, contribute significantly in revealing four associations between the two variables, including (i) supportive culture and reduced stress, (ii) high pressure and increased stress, (iii)autonomous culture and variable stress levels, and (iv) open culture and low-stress levels. Conclusions: The literature affirms a multifaceted link between employee workplace stress and organizational culture type. The findings show that these cultures are crucial in influencing the level of stress among employees. All four types were hypothesized to have a significant relationship with job stress.

• Steel and Composite Structures
• /
• v.34 no.5
• /
• pp.671-679
• /
• 2020

The new energy-based criterion, named Reinforcement Strain Energy Density (ReiSED), is proposed to investigate the fracture behavior of the cracked orthotropic materials in which the crack is embedded in the matrix along the fibers. ReiSED is an extension of the well-known minimum strain energy density criterion. The concept of the reinforced isotropic solid as an advantageous model is the basis of the proposed mixed-mode I/II criterion. This model introduces fibers as reinforcements of the isotropic matrix in orthotropic materials. The effects of fibers are qualified by defining reinforcement coefficients at tension and shear modes. These coefficients, called Reduced Stress (ReSt), provide the possibility of encompassing the fiber fraction in a fracture criterion for the first time. Comparing ReiSED fracture limit curve with experimental data proves the high efficiency of this criterion to predict the fracture behavior of orthotropic materials.

• Journal of Mechanical Science and Technology
• /
• v.18 no.1
• /
• pp.37-44
• /
• 2004

This paper presents an approach to optimally design the air bearing surface (ABS) of the head slider by using the approximation methods. The reduced basis concept is used to reduce the number of design variables. In the numerical calculation, the progressive quadratic response surface modeling (PQRSM) is used to handle the non-smooth and discontinuous cost function. A multi-criteria optimization problem is formulated to enhance the flying performances over the entire recording band during the steady state and track seek operations. The optimal solutions of the sliders, whose target flying heights are 12 nm and 9 nm, are automatically obtained. The flying heights during the steady state operation become closer to the target values and the flying height variations during the track seek operation are smaller than those for the initial one. The pitch and roll angles are also kept within suitable ranges over the recording band.