• IE interfaces
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• v.12 no.3
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• pp.448-457
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• 1999

Accelerated degradation is concerned with models and data analyses for degradation of product performance over time at overstress and design conditions. Although there have been numerous studies with accelerated degradation theory in reliability, very few actually apply to parametric statistical analyses. This paper shows how to analyze degradation data, provides tests for how well the assumptions hold. Reel sensors, a sort of photointerrupters in home VCR, hive been tested, and least-square analyses are used to illustrate our approach. Tests for linearity of the performance-time relationship, dependence of the lognormal distribution, and the standard deviation on time are performed. The mean life of tested sensors is assessed at about 414,000 hours, and the Arrhenius activation energy of this reaction is concluded to be 0.39 eV as results.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.179-185
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• 2004

Surface finish technology is highly demanded in the wide field of industry applications from ultra-precision parts to rough casting parts. Therefore, many kinds of surface finish technologies have been developed for each purpose. Because surface of a car's wheel cast is very rough it becomes the reason of the corrosion. This surface is coated to complement such problem but because surface is rough, the result of coating is not good and the coated metal peels off well. Therefore before the wheel is coated, it is necessary to grind the surface. In this study, we devised the plant to apply a barrel machining to improve the surface roughness and enhance the productivity. Also we could obtain the optimum barrel machining conditions for the proper surface roughness.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.6
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• pp.833-842
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• 2002

The purpose of this study was to investigate the visual sensibility of color combination far clothing. The survey had been done for the 42 color combination for clothing with 27 semantic differential bi-polar scales. The major findings of this research were as follows. 1. There were significant differences in the visual sensibility of color combination, especially in the difference according to the area(in Seoul and in Pusan). 2. As a result of the regression analysis, preference was related to buying desirable, gorgeous, fun, cheerful, attractive, harmonious and refined and the purchasing desire was related to favorite, comfortable, harmonious, sweet, and fun. Rich impression was related to refined, harmonious, elegance and attractive and pleasant feeling was related to sort, cheerful, attractive, clean and refined. 3. According to sensibility positioning, The color combination for clothing was classified by hard-soft, simple-gorgeous.

• The Journal of Korea Robotics Society
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• v.2 no.4
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• pp.341-345
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• 2007

This paper proposes an emotional interaction model between human and robot using an android. An android is a sort of humanoid robot that the outward shape of robot is almost the same as that of human. The android is a robot platform to implement and test emotional expressions and human interaction. In order to behave for the android like human, a structure of internal emotion system is very important. In our research, we propose a novel emotional model of android based on biological hormone and emotion space. Proposed emotion model has an advantage that it can represent emotion change as time by hormone dynamics.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2007.05a
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• pp.27-30
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• 2007

With lots of portable convergence mobile device coming out into the market, companies are now facing to take up consumers' needs. The products are popularized by 'skin function' in the field of hardware, whereas software wise, it's still a long way to follow up the needs. It's been hypothetically known that the Image of Sensitivity Adjective chosen by the users can increase the brand image and value creating capabilities through visualization. We collect the 'adjective' of images of recent products first and on that base, we sort out the most popular 'adjective' through grouping, then we actualize the image with that sample collective body. Then through analyses of the image, we find how they are correlated and what their elements are with the result.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.61-66
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• 2020

As asbestos-containing buildings are getting older, asbestos deconstruction works are increasing. As a result, accident risks such as falls, cuts, electric shocks, and suffocation are increasing. Existing studies are mostly about health management and institutional policy research and there is little research on work risk. So workplace risk assessments that are easily applicable in the field are required to be applied. Sealing is the first process of asbestos deconstruction and is the first step to ensure worker's safety. Job Safety Analysis(JSA) and Checklist were used to identify the risk factors and to calculate the level of the risk. By comparing the two risk assessment tools, it was figured out that the JSA is appropriate for the initial process and change of work procedure while Checklist is appropriate for repetitive work. Because the sealing process is sort and simple, it is unlikely to cause serious injury. But since the risk of falling and cuts are exist, safety education and supervision are necessary to maintain a safe working environment.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.2
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• pp.13-46
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• 2001

SDP (Semidefinite Programming), as a sort of “cone-LP”, optimizes a linear function over the intersection of an affine space and a cone that has the origin as its apex. SDP, however, has been developed in the process of searching for better solution methods for NP-hard combinatorial optimization problems. We surveyed the basic theories necessary to understand SDP researches. First, We examined SDP duality, comparing it to LP duality, which is essential for the interior point method, Second, we showed that SDP can be optimized from an interior solution in polynomial time with a desired error limit. finally, we summarized several research papers that showed SDP can improve solution methods for some combinatorial optimization problems, and explained why SDP has become one of the most important research topics in optimization. We tried to integrate SDP theories. relatively diverse and complicated. to survey research papers with our own perspective, and thus to help researcher to pursue their SDP researches in depth.

• Korean Journal of Human Ecology
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• v.6 no.2
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• pp.173-185
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• 1997

This study intends to suggest the considerations in the planning of production space of rice farming houses, based on their needs on the space and machinery for rice production. The 30 rice farming houses, in a village in Chungbuk province, responded for this study. Larger stalls and new built storehouses for grain or machinery showed changes in attached buildings after 1970s. Despite of the broad use of machinery in rice terming, however, only 1 or 2 houses in a village own and run it, and the planning of storehouse for machinery has to be done respectively. The sort and location of attached houses depend on the scale of rice farming. And because the production activities in the riceplanting or harvesting period collide with household ones, the considerations on the planning of efficient activity-oriented production space are offered in this study.

• Bulletin of the Korean Mathematical Society
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• v.53 no.3
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• pp.925-942
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• 2016

We study the structure of rings whose principal right ideals contain a sort of two-sided ideals, introducing right ${\pi}$-duo as a generalization of (weakly) right duo rings. Abelian ${\pi}$-regular rings are ${\pi}$-duo, which is compared with the fact that Abelian regular rings are duo. For a right ${\pi}$-duo ring R, it is shown that every prime ideal of R is maximal if and only if R is a (strongly) ${\pi}$-regular ring with $J(R)=N_*(R)$. This result may be helpful to develop several well-known results related to pm rings (i.e., rings whose prime ideals are maximal). We also extend the right ${\pi}$-duo property to several kinds of ring which have roles in ring theory.

• Communications of the Korean Mathematical Society
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• v.33 no.3
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• pp.741-750
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• 2018

Antoine showed that the properties of Armendariz and NI are independent of each other. The study of Armendariz and NI rings has been doing important roles in the research of zero-divisors in noncommutative ring theory. In this article we concern a new class of rings which generalizes both Armendariz and NI rings. The structure of such sort of ring is investigated in relation with near concepts and ordinary ring extensions. Necessary examples are examined in the procedure.