• Journal of the Korean Society for Heat Treatment
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• v.4 no.3
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• pp.54-62
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• 1991

The effect of tempering temperature on the ultrasonic propagation velocity at SCM 440 steel quenched from $870^{\circ}C$ and $1000^{\circ}C$ has been studied by metallurgical and crystallographical observation. The measurements of ultrasonic velocity were made on the specimen by appling an immersion ultrasonic pulse-echo technique with a constant frequency of 10 MHz. The quenched microstructure of this steel was a lath martensite. As the tempering temperature was increased, the martensite was transformed into the tempered martensite composed of cementite and carbide. The ultrasonic velocity increased with increasing the tempering temperature. It was thought that these were resulted from the microstructural transformation. The change of ultrasonic propagation velocity with quenching and tempering heat treatment was resulted from microstrain due to the change of internal stress. Considering these results concerning to the change of ultrasonic propagation velocity. the phenomena of microstructural transformation were estimated. Consequently, it was thought that the degree of quenching and tempered heat treatment of steel could be nondestructively evaluated with the change of ultrasonic propagation velocity.

• International Commerce and Information Review
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• v.10 no.3
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• pp.101-116
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• 2008

Future e-Trade RFID/USN distribution should satisfy the new needs of reasonable customers such as efficient supply of goods, presentation of information, and communication by developing intermediate and long-term strategies through analysis of industrial conditions and customers' needs. Through preferential application of new technology, knowledge-based e-Trade RFID/USN distribution environment and DB of industrial portal sites should be developed, RFID/USN infra such as Supply Chain Management(SCM) should be expanded, future-oriented knowledge-based services should be developed to prepare specific and realistic plans for proper UT(Ubiquitous Technology). Such change in e-Trade distribution environment should have historical and environmental backgrounds to suggest specific tasks and directions as a conversion of structural concept of engineering and trade theory for new u-Trade. Accordingly, this study is to present all the problems available in RFID/USN distribution, develop an organized and technological estimate model and provide a foundation to apply it efficiently. This study aims to present an interpretational foundation of RFID/USN distribution, rather than technical directions.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.4
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• pp.148-154
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• 2011

This paper presents u-COEX, Ubiquitous-Collaborative Online shopping EXecution system, for small- and mediam- sized business enterprises, based on EPCglobal network. The system is taking advantage of RFID technology promises to optimize the critical processes in the Supply Chain Management. The system consists of five major functions: integrated order management, realtime monitoring and analysis system of sales and inventory, decision support system, integrating with EPCglobal and RFID technology, and u-catalog feature. The prototype implementation was developed for mass electronic market complex and the result revealed the feasibility to be applicable to real market.

• Journal of Korean Medical classics
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• v.25 no.3
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• pp.13-22
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• 2012

Objective : This study was conducted to compare Sasang Constitutional Medicine (SCM) and Four Humor Theory (FHT). Method : 1. The theoretical comparison was focused on the central pillars of both theories, i.e., the theories of Hippocrates and his successor Galenos as well as Lee Je-ma. 2. Research papers on SCM and FHT were collected as follows. First, relevant papers were searched for using several electronic databases: Pubmed (http://www.pubmed.org.), NDSL (http://www.ndsl.kr/index.do), KISS (http://kiss.ksstudy.com), and RISS (http://www.riss4u.net.). Keywords were 'Sasang', 'constitution', 'constitutional medicine', 'humor theory', 'Hippokrates', 'Galenos', and "Dongeuisusebowon".In addition, relevant papers were searched for using the websites of The Korean Society for the History of Medicine(http://medhist.kams.or.kr), The Korean society of Oriental medical classics (http://www.wonjeon.or.kr), The Society of Sasang Constitutional Medicine (http://www.esasang.or.kr/new_home/main.htm),and The Korean Association of Oriental Medical Physiology (http://www.ksomp.or.kr). As a result, a total of 32 papers were included in the final selection. Result & Conclusion : In this study, a comparison was made between FHT and SCM in terms of physiology, pathology and therapy. We showedthat the theories share similarities as well as differences. However, in a practical sense, the two should be characterized based on their differences rather than their similarities. In conclusion, the two have something in common, but overall, they are remarkably different from each other.

• Transactions of Materials Processing
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• v.31 no.4
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• pp.207-213
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• 2022

In this study, variations in the microstructure and hardness of a low-carbon SCM415 steel with austenitizing temperature and cooling rate are investigated. When the austenitizing temperature is lower than the A₁ temperature (738.8 ℃) of the SCM415 steel, the microstructures of both the air-cooled and water-cooled specimens consist of ferrite and pearlite, which are similar to the microstructure of the initial specimen. When heat treatment is conducted at temperatures ranging from the A₁ temperature to the A₃ temperature (822.4 ℃), the microstructure of the specimen changes depending on the temperature and cooling rate. The specimens air- and water-cooled from 750 ℃ consist of ferrite and pearlite, whereas the specimen water-cooled from 800 ℃ consists of ferrite and martensite. At a temperature higher than the A₃ temperature, the air-cooled specimens consist of ferrite and pearlite, whereas the water-cooled specimens consist of martensite. At 650 ℃ and 700 ℃, which are lower than the A₁ temperature, the hardness decreases irrespective of the cooling rate due to the ferrite coarsening and pearlite spheroidization. At 750 ℃ or higher, the air-cooled specimens have smaller grain sizes than the initial specimen, but they have lower hardness than the initial specimen owing to the increased interlamellar spacing of pearlite. At 800 ℃ or higher, martensitic transformation occurs during water cooling, which results in a significant increase in hardness. The specimens water-cooled from 850 ℃ and 950 ℃ have a complete martensite structure, and the specimen water-cooled from 850 ℃ has a higher hardness than that water-cooled from 950 ℃ because of the smaller size of prior austenite grains.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.703-704
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• 2006

RFID/USN means a way of attaching RFID to all required objects to identify them and exchanging the required information through the network. High frequency (13.56MHz) has been commonly used in the field of processing management in Korea, and extremely short wave (433.92MHz) has been used for harbor logistics management by being attached to containers in the US. As for SCM field where we need to have a broader understanding, the research on $860{\sim}960MHz$, a sort of extremely short wave has been most actively conducted. Therefore, in-this study, in order to understand the features of all frequencies ranging and to design and implementation of RFID Middle System suitable for realizing u-Logistics by using those diverse frequencies.

• IMMUNE NETWORK
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• v.13 no.4
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• pp.133-140
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• 2013

Since the discovery of the immunomodulation property of mesenchymal stem cells (MSCs) about a decade ago, it has been extensively investigated whether MSCs can be used for the treatment of immune-related diseases, such as graft versus-host disease (GvHD). However, how to evaluate the efficacy of human MSCs for the clinical trial is still unclear. We used an MHC-mismatched model of GvHD (B6 into BALB/c). Surprisingly, the administration of the human MSCs (hMSCs) could reduce the GvHD-related mortality of the mouse recipients and xenogeneically inhibit mouse T-cell proliferation and $IFN-{\gamma}$ production in vitro. We recently established a new protocol for the isolation of a homogeneous population of MSCs called subfractionation culturing methods (SCM), and established a library of clonal MSC lines. Therefore, we also investigated whether MSCs isolated by the conventional gradient centrifugation method (GCM) and SCM show different efficacy in vivo. Intriguingly, clonal hMSCs (hcMSCs) isolated by SCM showed better efficacy than hMSCs isolated by GCM. Based on these results, the MHC-mismatched model of GvHD may be useful for evaluating the efficacy of human MSCs before the clinical trial. The results of this study suggest that different MSC lines may show different efficacy in vivo and in vitro.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.170-181
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• 2015

Generally, because individual agricultural product possesses its own distinctive characteristics and shows different characteristics at each stage of the agricultural supply chain, it is necessary to develop a proper enterprise architecture for managing information system. In this paper, we propose an enterprise architecture based on RFID/USN technology that can be used as a reference enterprise architecture for u-IT application in the agriculture sectors, which is called the u-Farm enterprise architecture with taking heterogeneous characteristics of agricultural products into account for. In addition, we also developed the RFID/USN middleware platform as a core infrastructure technology. Fo evaluation of the performance of the proposed u-Farm architecture and the RFID/USN middleware platform, the field-trial evaluation at the apple Agricultural Processing Center (APC) has been executed and the results shows that the proposed architecture and platform perform well in terms of information integration over the whole SCM process from the farming stage to delivering statge to the customers. It is expected that the proposed u-Farm enterprise architecture can be utilized as a standard information architecture, and the RFID/USN middleware platform can be a infrastructure platform for future u-IT based information technology applications and services in the agricultural environment.

• Advances in concrete construction
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• v.5 no.1
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• pp.31-48
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• 2017

Supplementary cementitious materials (SCM) have turned out to be a vital portion of extraordinary strength and performance concrete. Metakaolin (MK) is one of SCM material is acquired by calcinations of kaolinite. Universally utilised as pozzolanic material in concrete to enhance mechanical and durability properties. This study investigates the fresh and hardened properties of conventional concrete (CC) and self compacting concrete (SCC) by partially replacing cement with MK in diverse percentages. In CC and SCC, partial replacement of cement with MK varies from 5-20%. Fresh concrete properties of CC are conducted by slump test and compaction factor tests and for SCC, slump flow, T500, J-Ring, L-Box, V-Funnel and U-Box tests. Hardened concrete characteristics are investigated by compressive, split tensile and flexural strengths at age of 7, 28 and 90 days of curing under water. Carbonation depth, water absorption and density of MK based CC and SCC was also computed. Fresh concrete test results indicated that increase in MK replacement increases workability of concrete in a constant w/b ratio. Also, outcomes reveal that concrete integrating MK had greater compressive, flexural and split tensile strengths. Optimum replacement level of MK for cement was 10%, which increased mechanical properties and robustness properties of concrete.

• Journal of Digital Convergence
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• v.6 no.4
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• pp.137-145
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• 2008

Embedded industry has emerged as one of the important industry for u-IT based application service. Technology development related to embedded hardware and software provides the base for the development of U-IT convergence industry. This study intends to suggest a research model to investigate the influence of industry, organization, technology factors on technology performance in the embedded companies. This study adopted research variables such as global network, local network, industry intensity, and technology capability as independent variables, with technology performance as a dependent variable from the existing literatures. The purpose of this study is to analyze the influence of industrial and organizational factors on technology performance of embedded companies SCM systems, including the moderating effect of government support. 94 companies data were collected by survey. The result of this empirical study is summarized as follows. First, local network and technology capability are the important determinants to influence technology performance of embedded companies in direct effect model. Second, global network and industry intensity has more positive influence on technology performance of embedded companies through a moderating variable of government support.