• Steel and Composite Structures
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• v.34 no.5
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• pp.681-698
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• 2020

The paper addresses contribution to the modeling and optimization of major machinability parameters (cutting force, surface roughness, and tool wear) in finish dry hard turning (FDHT) for machinability evaluation of hardened AISI grade die steel D₃ with PVD-TiN coated (Al₂O₃-TiCN) mixed ceramic tool insert. The turning trials are performed based on Taguchi's L₁₈ orthogonal array design of experiments for the development of regression model as well as adequate model prediction by considering tool approach angle, nose radius, cutting speed, feed rate, and depth of cut as major machining parameters. The models or correlations are developed by employing multiple regression analysis (MRA). In addition, statistical technique (response surface methodology) followed by computational approaches (genetic algorithm and particle swarm optimization) have been employed for multiple response optimization. Thereafter, the effectiveness of proposed three (RSM, GA, PSO) optimization techniques are evaluated by confirmation test and subsequently the best optimization results have been used for estimation of energy consumption which includes savings of carbon footprint towards green machining and for tool life estimation followed by cost analysis to justify the economic feasibility of PVD-TiN coated Al₂O₃+TiCN mixed ceramic tool in FDHT operation. Finally, estimation of energy savings, economic analysis, and sustainability assessment are performed by employing carbon footprint analysis, Gilbert approach, and Pugh matrix, respectively. Novelty aspects, the present work: (i) contributes to practical industrial application of finish hard turning for the shaft and die makers to select the optimum cutting conditions in a range of hardness of 45-60 HRC, (ii) demonstrates the replacement of expensive, time-consuming conventional cylindrical grinding process and proposes the alternative of costlier CBN tool by utilizing ceramic tool in hard turning processes considering technological, economical and ecological aspects, which are helpful and efficient from industrial point of view, (iii) provides environment friendliness, cleaner production for machining of hardened steels, (iv) helps to improve the desirable machinability characteristics, and (v) serves as a knowledge for the development of a common language for sustainable manufacturing in both research field and industrial practice.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.141-154
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• 2002

More efforts have been given to solve the problems related to computer software by process assessment. ISO/IEC 15504(SPICE) has been developed as standardized means for process assessment. The purpose of this paper is to design and implement a process assessment system which is appropriated to the Korean assessment environment based on ISO/IEC 15504. Referring documents are: IS0/1EC 15504 standardized documents, the assessment provisions of the SPICE committee in Korea, and research papers applied the existing process assessment system to real cases. Among a lot of processes, this system is designed for (ENG2). The proposed system in the paper will support the whole process of assessment, presenting the goals and end-products for each assessment step and making it possible to compose and save the product on the same screen. In determining process rating, assessors can retrieve the saved data and documents. By doing so, the system will improve reliability in process rating. The proposed system includes 7 steps of pre-assessment and 9 steps of actual assessment in order to fully prepare assessors for process assessment. And each step has been standardized to improve user-friendliness. This system is designed to provide assessors with specific details of standardized documents, the goals of the process, outcomes of implementing the process, and presentations of base practices and input/output products. Above all, the system automatically generates an assessment rating, by calculating based on input data which assessors make out. It also presents outcomes graphically.

• The Research Journal of the Costume Culture
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• v.21 no.1
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• pp.57-65
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• 2013

With environmental pollution becoming a serious problem, recently there has been increased interest in the environment and health. In addition, the development of materials for environmentally friendly and functional clothing has increased. Environmentally friendly products that use bark fibers of the mulberry(dak) tree are expressed in terms of dak fiber and Hanji yarn. This research analyzed consumer's perceived images of Hanji and Hanji yarn infant clothing. The research results are as follows. Based on analyzing images of Hanji and Hanji yarn, Hanji was categorized into four images that can be described as natural, pure, decorative, and functional, and Hanji yarn infant clothing was categorized into three images that can be described as natural, decorative, and functional. Based on the analysis of well-being elements in subjects' lifestyles, the following four inclinations were found: environmental friendliness, pursuit of novelty, life care, and environmental protection. On this basis, the subjects were categorized into three groups: the trend-pursuing group, the life-care group, and the social responsibility group. Subjects' perceived images of Hanji and Hanji yarn infant clothing were investigated, and these products were found to have a strong image of being Korean, traditional, and natural, while being weakly perceived as comfortable, functional, and practical. Analyzing the correlation between images of Hanji and Hanji yarn infant clothing and lifestyle groups revealed that these products were not perceived differently according to group. This study showed that Hanji and Hanji yarn are terms that are commonly associated with positive clothing material. However, both Hanji and Hanji yarn are perceived negatively in terms of functional image, which is an important factor in clothing material. In addition, even among consumers who pursue a lifestyle based on well-being, the functional image of Hanji yarn was not perceived highly. Hence, it is necessary to further examine the effect of terms such as Hanji and Hanji yarn on consumer choices. Therefore, caution is considered needed when using such terms in the marketing of related products.

• 한국초등상담교육학회:학술대회논문집
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• 2004.01a
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• pp.137-168
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• 2004

The purpose of this study is to find the effect of group counseling program based on reality therapy that is developed by researcher and to investigate whether the program can decrease the academic stress of elementary school students. For this study, firstly a framework for academic stress decrease programs is established and a program is developed in accordance with the framework. Secondly, in order to verify the effect of the program, both quantitative and qualitative methods were applied to 6th grade students through a academic stress test. Experimental group and control group is composed of 18 students, each. During a two month-experimental period, group counseling program based on reality therapy was implemented to the experimental group for 10 sessions but not to the control group. The program included nicknaming, recreation activities to promote friendliness among participants and other various activities to decrease the academic stress. The results of the quantitative and statistical research are as follows: First, group counseling program based on reality therapy is effective to decrease of elementary school students' academic stress. Second, sub factor(such as perceptions of academic stress cause, symptoms of academic stress)of academic stress is significantly decreased in experimental group. But no significant difference is found in control group. Third, for some sub factor(career, friend-relationship, house-environment, behavior-symptom), an independent-sample test and a paired-sample test showed different results: the paired-sample test showed no significant differences in experimental group while the independent-sample test showed significant decrease of academic stress. The results of the qualitative research based on student commentaries on the program is as follows: First, experimental group students report that the program based on reality therapy was effective to decrease of academic stress. Second, experimental group students' commentaries shows that students could remember the WDEP, 'act' factor and acquire the solution of academic stress. Third, for a group counseling, students reported the interest about positive feedback, searching on themselves, growth of human-relationship. This means that the program developed on this study is suitable for group counseling program. In conclusion, this study proves that group counseling program based on reality therapy is effective to decrease of elementary school students' academic stress by increasing individual internal-control. Therefore, it is necessary that we should develop and apply similar program to elementary school students in other to decrease students' academic stress. school students in other to decrease students' academic stress.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.3
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• pp.43-49
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• 2010

Direct printing technology is an attractive metallization method, which has become immerging as "Green technology" to the conventional photolithography, on account of low cost, simple process and environment-friendliness. In order to commercialize the printed electronics in industry, it is essential to evaluate the electrical properties of conductive circuits using direct printing technology. In this contribution, we focused on the electrical characteristics of inkjet-printed circuits. A Cu nanoink was inkjet-printed onto a Bisaleimide triazine(BT) substrate with parallel transmission line(PTL) and coplanar waveguide(CPW) type, then was sintered at $250^{\circ}C$ for 30 min. We calculated the resistivity of printed circuits through direct current resistance by the measurement of I-V curve: the resistivity was approximately 0.558 ${\mu}{\Omega}{\cdot}cm$ which is about 3.3 times that of bulk Cu. Cascade's probe system in the frequency range from 0 to 30 GHz were employed to measure the Scattering parameter(S-parameter) with or without a gap between the substrate and the probe station chuck. The result of measured S-parameter showed that all printed circuits had over 5 dB of return loss in the entire frequency range. In the curve of insertion loss, $S_{21}$, showed that the PTL type circuits had better transmission of radio frequency (RF) than CPW type.

• Journal of the HCI Society of Korea
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• v.11 no.2
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• pp.23-30
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• 2016

The Internet of Things(IoT) market is growing exponentially as a core growth engine of the future. Major companies of the world are competitively providing the IoT services to dominate the IoT market first and create ecosystem around their companies. In order to establish the IoT services and contribute to the related industry, they will need to make efforts to provide the IoT services that the users desire, and which the users can have new experiences with. Thus, we attempted to draw out the user value factors to help successful IoT service development. For this purpose, we explored the meaning and concept of IoT, drew out a trend matrix of IoT through the literature review related to IoT and conducted a survey through the user values established by the literature related to IoT and the focus group interviews. As a result, we identified thirteen user value factors of the IoT services, which are manageability, relationship, familiarity, expandability, simplicity, entertainment, safety, economic feasibility, compensation, automation, rapidity, informativity and environment-friendliness. This study is expected to be used as a basic material in understanding the IoT services and as standards or assessment items to develop the IoT services that the users want.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.485-500
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• 2020

Due to various advantages such as small facilities, ease of construction and so on, the grouting technology which is widely used in construction field has developed remarkably compared with the past. However, the efforts to improve the homogeneity of quality, long-term durability and environmental problems have been continued. In recent years, new grouting method has been developed in order to solve problems such as low strength, durability and leaching phenomenon of liquid glass (sodium silicate) grouting material in Korea. A newly developed method integrates the injection material with the ground by the self-healing material of crystallization growth type. For this reason, it is known that improvement of the durability and water quality of the ground, prevention of leaching, and environment friendliness can be expected. The present study applied a newly developed method to test sites and verified its effect such as injection range, improvement effect, waterproofing performance and so on. Standard penetration test, field permeability test, borehole shear test, pressuremeter test and pH test were conducted, and the results were compared between before and after developed method application. As results of tests, the field applicability and improvement effect of developed method were proved to be excellent.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.355-358
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• 2015

BACKGROUND: Changes in Korea's agricultural soil properties were analyzed at a four-year interval from 1999 to 2002 on a national scale and used as basis for the determination of the appropriate agricultural policy on maintaining food safety and soil quality. The scope of this study ideally requires sampling thousands of paddy, greenhouse, upland and orchard land across the country, however, due to limitations in economic and manpower resources, it was deemed necessary to reduce sampling site to greenhouse soil. In this study, we try to investigate the applicability of cultivated crops as criteria for selecting representing fields in greenhouse soils.METHODS AND RESULTS: Soil samples were collected from red pepper, oriental melon, watermelon and strawberry cultivated soil. Principal components analysis (PCA) was performed on soil chemical properties of the selected fields: pH, electron conductivity (EC), available phosphate (Av-P₂O₅), organic matter (OM), and exchangeable cation (Ex.-K, Ca, and Mg). Soil chemical properties of oriental melon cultivated soil was separated from red pepper, watermelon, and strawberry cultivated soil on PC1 and red pepper cultivated soil was separated from watermelon cultivated soil on PC2. Position on PC1 was strongly correlated with pH, Ex.-Ca and Ex.-Mg and position on PC2 was strongly correlated with OM and Av-P₂O₅.CONCLUSION: The soil chemical properties of greenhouse soil was assorted amongst the different crops. Therefore, the cultivated crops as a criteria for the selection of representative field in greenhouse soil would be used in the future.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.37-43
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• 2008

Inorganic injection material, which is one of the ground improvement materials, consists of cement accelerator and inorganic micro particle. The inorganic injection material is known to overcome the major limitations of water glass type improvement materials, which are leaching and accompanying strength loss. The inorganic injection material is superior in durability and strength, and environmentally friendly since leaching is prevented. In this study, the effectiveness and environment-friendliness of the MIS(Micro Injection-process System) using the inorganic injection material is compared to SGR, which uses the water glass. The performed tests were unconfined compression test, chemical resistance test, and fish poison test. The unconfined compression tests showed that the MIS results in 1.7 times higher 28 day strength compared to the SGR. In addition, the strength continually increased with time for the MIS, while it decreased for the SGR. The chemical resistance tests indicated that the rate of change in length using the MIS is 10~25 times smaller than when using the SGR. The fish poison test proved that MIS was more environmentally friendly. The analysis of chemical ingredients of leached showed that the amount of $Cr^{6+}$, Pb and Si leached from the MIS is less compared to the SGR. Accordingly, the MIS grout is more high-strength than existing SGR grout. It is excellent in shortening of construction period, structural stability of foundation and environmentally friendly. So, it is considered that it has not little the problem about groundwater pollution.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.4
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• pp.67-78
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• 2016

Recently many countries around the world are actively promoting smart city projects to address various urban problems such as traffic congestion, housing shortage, and energy scarcity. Due to development of the Internet of Things (IoT), the development of a smart city with sustainability, convenience, and environment-friendliness was enabled through the effective control and reuse of urban resources. The purpose of this study is to analyze the technical trends of IoT and present a development plan for smart city which is one of the applications of the IoT. To this end, the news articles of the Electronic Times between 2013 and 2015were analyzed using the text mining technique and smart city development cases of other countries were investigated. The analysis results revealed the close relationships of big data, cloud, platforms, and sensors with smart city. For the successful development of a smart city, first, all the interested parties in the city must work together to create new values throughout the entire process of value chain. Second, they must utilize big data and disclose public data more actively than they are doing now. This study has made academic contribution in that it has presented a big data analysis method and stimulated follow-up studies. For the practical contribution, the results of this study provided useful data for the policy making of local governments and administrative agencies for smart city development. This study may have limitations in the incorporation of the total trends because only the news articles of the Electronic Times were selected to analyze the technical trends of the IoT.