• KIEAE Journal
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• v.10 no.3
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• pp.89-96
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• 2010

In comparison with ordinary or heavy-weight concrete, light-weight air void concrete has the good aspects in optimizing super tall structure systems for the process of design considering wind load and seismic load by lightening total dead load of buildings and reducing natural resources used. Light-weight air void concrete has excellent properties of heat and sound insulating due to its high amount porosity of air voids. So, it has been used as partition walls and the floor of Ondol which is the traditional Korean floor heating system. Under the condition of which the supply of light-weight aggregates are limited, the development of light-weight concrete using air voids is highly required in the aspects of reduced manufacturing prices and mass production. In this study, we investigated the physical properties and thermal behaviors of specimens that applied different mixing ratios of foaming agent to evaluate the possibility of use in the structural elements. We proposed the estimating equation for compressive strength of each mix having different ratio of foaming agent. We also confirmed that the density of cement matrix is decreased as the mixing amount of foaming agent increase up to 0.6% of foaming agent mixing ratio which was observed by SEM. Based on porosity and compressive strength of control mortar without foaming agent, we built the estimating equations of compressive strength for mortars with foaming agent. The upper limit of use in foaming agent is about 0.6% of the binder amount. Each air void is independent, and size of voids range from 50 to $100{\mu}m$.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1075-1080
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• 2014

This study aims at dedicating to relevant technology fields by suggesting design methods of structures and estimating their safety in relation to substructure for offshore wind power requiring high safety to various environment conditions. Especially, with respect to 5MW Offshore Wind Power System, this study will provide information about major wind directions and duration in combination with the developing wave climate at the test field. Therefore, connections between wind fields and approaching wave trains will be estimated and their intensity, direction and time shift will be pointed out. Furthermore, the local pressure distribution of breaking waves will be investigated by physical and numerical modeling. The currently applied structural and fatigue assessment of support structures for offshore wind energy converters is based on common design rules. Normally, constructions in structural engineering are treated as limited, single structures. This means that varying aspects of manufacturing are considered by high safety factors.

• Journal of the Korea Furniture Society
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• v.20 no.2
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• pp.166-174
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• 2009

Most of the furniture in the past was dedicated to its original use such as storage and accommodation of articles or sitting tools, but the concept of furniture in contemporary indoor spaces is gradually increasing in its meaning while exchanging close impacts with other spatial components. Indeed, in contemporary furniture, a component other than furniture constituting a space would sometimes serve the common roles of furniture or sometimes furniture would include all indoor objects used to make people's living more convenient. This study reviewed the meaning of furniture and changes in its roles in contemporary indoor spaces and summarized the characteristics presenting a few examples. First, in contemporary indoor spaces, furniture as an independent object does not having a meaning any more. The fusion of functions with other components constituting indoor spaces is the most important characteristics in contemporary furniture and it has been already attempted in diverse ways through fusion with buildings surpassing fusion with other pieces of furniture or electric home appliances. Second, the arrangement conforming to the roles required by spaces and diverse forms of attempts are essential. Since furniture is an item the most closely related to human residential life, studies on human behaviors in spaces must precede. The efforts to enhance work efficiencies and used limited spaces more efficiently will be continued and explorations of new forms should be also continued. Third, with regards to manufacturing methods, new technologies should be applied more widely and furniture materials must be diversified through the use of new materials including not only cutting-edge new materials but also all the materials that can be applied to furniture such as conventional natural materials and environment friendly materials that can be recycled.

• Journal of Technology Innovation
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• v.21 no.1
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• pp.199-228
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• 2013

Globalization has been accelerated in today's business environment. In this situation, the opening of economies can be either an opportunity or a treat for small and medium sized enterprises (SMEs) who have limited resources. Especially, managerial perception to the opening of economies carries on significant meaning because managerial perception determines future responses and strategies. Therefore, this study examined which innovation activities are related with SMEs' positive perception to the opening of economies. The activities of innovation are classified by types of generic strategy. Also, this study scrutinized the moderating effects of external search strategy and market entry strategy. In order to test hypotheses, this study analyzed data on Korean manufacturing firms collected in the Korean Innovation Survey (KIS). As a result, SMEs conducting innovation for differentiation strategy perceived the opening of economies positively. Search breadth and search depth moderated this relationship negatively and the first entry strategy moderated this relationship positively.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.564-573
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• 2018

External environment of enterprises are rapidly changing brought about mainly by global competition, cost and profitability pressures, and emerging new technology. In particular, frequent change of customer requirements is a tough challenge to manufacturing company. To cope with these challenges, a production planning and scheduling (PP&S) function might be established to provide accountability for both customer service and operational efficiency. PP&S deals with short-term decision making in the production process of whole supply chain. The task of PP&S is to seek a balance between customer orders and limited resources. At present, many PP&S software solutions have been utilized in many enterprises to generate a realistic production plan and schedule efficiently. The aim of this paper is to analyze the PP&S functionalities and its system architecture from the perspective of SCM (Supply Chain Management), and propose the PP&S solution classification framework to facilitate the comparison among various solutions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.29-37
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• 2017

This papers focuses on remanufacturing processes in a closed loop supply chain. The remanufacturing processes is considered as one of the effective strategies for enterprises' sustainability. For this reason, a lot of companies have attempted to apply remanufacturing related methods to their manufacturing processes. While many research studies focused on the return rate for remanufacturing parts as a control parameter, the relationship with demand certainties has been studied less comparatively. This paper considers a closed loop supply chain environment with remanufacturing processes, where highly fluctuating demands are embedded. While other research studies capture uncertainties using probability theories, highly fluctuating demands are modeled using a fuzzy logic based ambiguity based modeling framework. The previous studies on the remanufacturing have been limited in solving the actual supply chain management situation and issues by analyzing the various situations and variables constituting the supply chain model in a linear relationship. In order to overcome these limitations, this papers considers that the relationship between price and demand is nonlinear. In order to interpret the relationship between demand and price, a new price elasticity of demand is modeled using a fuzzy based nonlinear function and analyzed. This papers contributes to setup and to provide an effective price strategy reflecting highly demand uncertainties in the closed loop supply chain management with remanufacturing processes. Also, this papers present various procedures and analytical methods for constructing accurate parameter and membership functions that deal with extended uncertainty through fuzzy logic system based modeling rather than existing probability distribution based uncertainty modeling.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.549-555
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• 2002

Tensile strength of CFRP (Carbon Fiber Reinforced Polymer) is approximately 10 times higher than that of the steel reinforcement, but the design strength of CFRP is normally limited by unpredictable bond failure between RC and CFRP. Many researches concerned with bond behavior between RC and CFRP have been carried out to prevent the bond failure of RC beam strengthened by CFRP, but the national design code for design bond strength of CFRP has not been constructed. In this study, three beam specimens strengthened by CFRP under the parameters of bonded length were tested to derive the design bond strength of CFRP for the RC flexural members. Each bonded length was calculated based on the bond strength of JCI and CFRP manufacturing company. Also, another two beam specimens strengthened by CFRP were tested to inspect the construction environment effects such as mixing error of epoxy resin, and the amount of epoxy primer. From the test results, it is concluded that the maximum design bond strength of CFRP to RC flexural member is considered to be $\tau$a =8 kgf/㎠.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.283-309
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• 1992

This study examines work and family life of married women employed in a manufacturing industry. Data were gathered from the use of fact-to-face interview method from a sample of 230 married working women. The major findings of this study can be summarized as follows : (1) With high rates of change of job, most of the respondents remain unstable in their working situation. It was shown that the important factors influencing job satisfaction of married women are women's life cycle, degree of contribution of wife's income toward total family income, and husband's attitude toward wife's empolyment. The degree of job satisfaction is also strongly influenced by labor structural factors such as pay, work environment and fringe benefits. (2) The amount of household labor time was limited by job-related factors rather than by family-related factors, because among these working women employment itself is necessarily for their subsistance. (3) It was shown that wives participated more actively in their marital communications than their husbands. Most of the respondents showed the syncratic type of the decision making patterns, but this results does not necessarily mean wives exercised an equal power with their husbands. The economic factors and the emotional instability of the husband are the ones mostly influencing marital conflicts of the employed women. It was found that the respondents easily revealed marital conflicts related to personal problems of their husbands(such as extramarital affairs, gambling and alchoholism). However, they tried to overcome the structural conflicts related to authoritarian attitudes of their husbands or economic problems without any complaints. (4) Mothers have difficulty in controlling their adolescent children, due to the weakening of parental authority. Although most of the respondents perceived their employment as having negative impacts on their children, they still have high expectations toward their children. Inspite of low degree of father role expectations and facther role performance of their husbands, most of the respondents anticipated expressive roles as well as traditionally instrumental role from their husbands. Finally, these findings would help us determine family welfare policies in Korea. Improvements in paid and household labor structure of married women should be accomplished at the national level. Also, the acting programs for parent education, marital councelling services, and law enforcement for equal employment between men and women should be provided in our society.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.4
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• pp.293-300
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• 2016

The Voice recognition is one of convenient methods to communicate between human and robots. This study proposes a speech recognition method using speech recognizers based on Hidden Markov Model (HMM) with a combination of techniques to enhance a biped robot control. In the past, Artificial Neural Networks (ANN) and Dynamic Time Wrapping (DTW) were used, however, currently they are less commonly applied to speech recognition systems. This Research confirms that the HMM, an accepted high-performance technique, can be successfully employed to model speech signals. High recognition accuracy can be obtained by using HMMs. Apart from speech modeling techniques, multiple feature extraction methods have been studied to find speech stresses caused by emotions and the environment to improve speech recognition rates. The procedure consisted of 2 parts: one is recognizing robot commands using multiple HMM recognizers, and the other is sending recognized commands to control a robot. In this paper, a practical voice recognition system which can recognize a lot of task commands is proposed. The proposed system consists of a general purpose microprocessor and a useful voice recognition processor which can recognize a limited number of voice patterns. By simulation and experiment, it was illustrated the reliability of voice recognition rates for application of the manufacturing process.

• Journal of the Korea Furniture Society
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• v.17 no.4
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• pp.1-13
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• 2006

This study attempted to identify the characteristics of chair design from furniture company, $K{\ddot{a}}llemo$, the furniture manufacturer in Sweden manufacturing mostly the limited edition of art furniture on the basis of the unique management philosophy. There are 12 artists manufactured chairs for $K{\ddot{a}}llemo$. Of them, this study selected 4 artists-Sigurdur Gustafsson, John Kandell, Komplot Design, Mats Theselius-who designed at least more than three chairs. Total 25 chairs were analyzed; 6 from Sigurdur Gustafsson, 8 from John Kandell, 3 from Komplot Design and 8 from Mats Theselius. The chair structure was divided into three parts, seat, back and structure and analyzed by material, color, type of legs and finishing. The following results were derived from the study. First, $K{\ddot{a}}llemo$ secured the regular customers who want to possess the chairs as the artistic works by continuing the small quantity mass-production system insisting that the maximum quantity of production is 360 pieces and the minimum quantity is 33 pieces. Second, the sufficient time and cost were invested in the initial phase of design. This approach seems to be deviated from the traditional business system that has to create the revenue at a glance, but ultimately induces the commercial success by exponentially increasing the revenue through the creation of various product lines. Third, $K{\ddot{a}}llemo$ provides the space that the artists who work for $K{\ddot{a}}llemo$ can sufficiently enjoy the mental composure and luxury required for the designers by strictly selecting the artists and providing the best environment for enabling the creative activities that look like the pure art area. This study enables the further analysis and research on other collections of $K{\ddot{a}}llemo$ that mass-produces the chairs on the basis of the unique philosophy in the world as well as in Sweden using more various kinds of analysis frameworks.