• Composites Research
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• v.34 no.5
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• pp.317-322
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• 2021

When a complex load such as torsion, low-speed impact, or fatigue load is applied, the properties in the thickness direction are weakened through microcracks inside the material due to the nature of the laminated composite material, and delamination occurs. To prevent the interlaminar delamination, various three-dimensional reinforcement methods such as Z-pinning and stitching, and structural health monitoring techniques that detect the microcrack of structures in real time have been continuously studied. In this paper, the single-lap joints with I-fiber stitching process were manufactured by a co-curing method and their strengths and failure detection capability were evaluated. AE and electric resistance method were used for detection of crack and failure signal and electric circuit for signal analysis was manufactured, and failure signal was analyzed during the tensile test of a single-lap joint. From the experiment, the strength of the single lap joint reinforced by I-fiber stitching process was improved by about 44.6% compared to the co-cured single lap joint without reinforcement. In addition, as the single-lap joint reinforced by I-fiber stitching process can detect failure in both the electrical resistance method and the AE method, it has been proven to be an effective structure for failure monitoring as well as strength improvement.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.134-147
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• 2019

The purpose of this study was to analyze the functional unit system of NCS landscape field for correction and supplementation of NCS landscape field and the contents of the four-year college landscape course subject. First, 24 unconsolidated four-year universities were selected, and FGI was conducted and verified for 816 courses in 24 universities. The results of the study are summarized as follows, with three sections three, nine divisions and 65 sub-category. First, landscape design subjects accounted for 40.0% of the subjects organized by four-year universities. In addition, the ratio of 12.9% for ecological landscape, 11.3% for landscape construction, 10.2% for others, 10.0% for landscape information, 6.6% for landscape culture and 3.7% for landscape management was surveyed. Balanced and efficient modification and reinforcement of NCS is required in the future. Second, 10(18.9%) units with matching NCS performance criteria and educational objectives were found to be capable of different units(18.9%), 15(28.3%), and 37subjects with inconsistent NCS unit capability (56.9%). Third, looking at the criteria for the reference of each unit of capability presented by the NCS, it is deemed that one unit of capability should be organized separately to improve the practical ability, since it includes the contents of basic knowledge learning. Fourth, the objectives pursued on the basis of the contents of the NCS capability unit and four-year college curriculum were developed by focusing on the development of unit capabilities in the field of landscape construction and landscape management compared to the field of landscape design. It has been shown that a balance is needed for future development. This study is intended to put forward further research that re-examine specific curriculum assessment criteria that have not been classified in the course of classifications based on the curriculum handbook, which excludes interferences from each school.

• Journal of the Korean Geosynthetics Society
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• v.9 no.2
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• pp.41-50
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• 2010

The concrete lining of a tunnel constructed by NATM used to be regarded as facing material which does not support any load from the surrounding ground. But the recent appraisal of the decrepit tunnels revealed that rockbolts and shotcrete deteriorate with time resulting in loss of supporting capability. Consequently, concrete lining has to support part of the load which used to be supported by rockbolts and shotcrete, and thus should be regarded as the final supporting structure in a tunnel. One of the common, and perhaps the most serious problem in concrete lining is the longitudinal cracks taking place at the tunnel crown. The longitudinal cracks, mostly related to the construction procedures, can be developed by many reasons such as the lack of thickness, wrong materials, bad curing environment, and excessive external forces. Many efforts has been made to control and suppress these cracks but efficient and economic way is yet to be found. For efficient crack control in concrete lining, reinforcement by composite fibers, which is the mixture of steel fiber and nylon fiber, is suggested in this study.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.174-180
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• 2005

Antigen presenting cells (APCs), dendritic cells (DCs) and macrophages, playa critical role not only in the initiation of immune responses, but also in the induction of immune tolerance. In an effort to regulate immune responses through the modulation of APC function, we searched for and characterized APC function modulators from natural products. Bifidobacterium pseudocatenulatum SPM1204 (SPM1204) isolated from feces of healthy Korean in the age of 20s was used in this experiment. DCs and macrophages were cultured in the presence of supernatants of SPM 1204 and then examined for their activities for the presentation exogenous antigen in association with major histocompatibility complexes (MHC) and macrophage activation. SPM1204 increased class I MHC-restricted presentation of exogenous antigen (cross-presentation) in a DC cell line, DC2.4 cells. The RAW 264.7 cell line was used to test the nonspecific effect of immune reinforcement of SPM1204 as a source of biological regulating modulator for the macrophage activation, include nitric oxide (NO) production and cytokine production. Results showed that the production of NO, tumor necrosis factor (TNF)-$\alpha$, interleukin 1 (IL-1)-$\beta$ and morphological changes in macrophages were largely affected by SPM1204 in a dose-dependent manner. Our results demonstrated that SPM1204 promote cross-presentation of dendritic cells as well as the induction of NO, TNF-$\alpha$ production, and activation of macrophage.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.307-316
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• 2011

The objective of this study is to figure out some specific features that were found during the adaptation process of migrant women by marriage to their local community, and also to elicit certain practical implications to facilitate their adaptation, based on the findings. For data collection, in-depth interviews were conducted with eight migrant women by marriage and the interviews were tape-recorded for transcription. For analysis, phenomenological method, particularly, Colaizzi method was adopted, by which meaningful statements in the data were categorized into themes and theme clusters. A total of 7 thematic unts, 17 themes and 47 meanings were elicited from the analysis and these 7 thematic units were "reinforcement of inner capability"; "cultural assimilation"; "to be a limited benefit receiver"; "no human network"; " impossible to be optimistic about future"; "hoping to reside in their local community"; "possible to leave Korea." Finally, this study suggested the implications for social welfare practices to facilitate the adaptation of immigrant women by marriage in their local community.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.9-17
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• 2012

In 1960's, Korea had concentrated on economic development, in the meantime the existing problem which is an avoiding rural settlement phenomenon such as a farming population decrease, an unstabel income, poor surroundings, etc. could intensify. And because of an exodus from agricultural area caused by industrialization and a fall of agricultural farm price as a result of domestic agricultural market opening in accordance with FTA, in 2004 Korean government excuted the integrated rural-village development plan as a measure to provide more support for agricultural villages. The integrated rural-village development plan means that inter-connected with villages which have potnetial and developed it as a unit of small-zone, also we can assume it a Down-up development type because residents participate and lead this plan directly. But, this plan made progress rapidly as a countmeasure of government so, it needs to evaluate for completed project area and make an improvement for a sustainable undertaking. Therefore, this study categorized project contents systematically into two parts of Hardware and Software, after that composed of 4 large-parts, 13 mid-parts and 43 small-parts from Inje-Yongdai zone which was designated for an integrated rural-village development plan in 2004. And a result of analysis for project contents priorities by hierarchy analysis method showed the Regional capability reinforcement is selected for the most important project content by 3 stakeholders who are specialists (514pts.), Korea Rural Community Corporation staffs (694pts.), local government officers (688pts.)

• Smart Structures and Systems
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• v.15 no.4
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• pp.997-1018
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• 2015

Structural health monitoring along with damage detection and assessment of its severity level in non-accessible reinforced concrete members using piezoelectric materials becomes essential since engineers often face the problem of detecting hidden damage. In this study, the potential of the detection of flexural damage state in the lower part of the mid-span area of a simply supported reinforced concrete beam using piezoelectric sensors is analytically investigated. Two common severity levels of flexural damage are examined: (i) cracking of concrete that extends from the external lower fiber of concrete up to the steel reinforcement and (ii) yielding of reinforcing bars that occurs for higher levels of bending moment and after the flexural cracking. The purpose of this investigation is to apply finite element modeling using admittance based signature data to analyze its accuracy and to check the potential use of this technique to monitor structural damage in real-time. It has been indicated that damage detection capability greatly depends on the frequency selection rather than on the level of the harmonic excitation loading. This way, the excitation loading sequence can have a level low enough that the technique may be considered as applicable and effective for real structures. Further, it is concluded that the closest applied piezoelectric sensor to the flexural damage demonstrates higher overall sensitivity to structural damage in the entire frequency band for both damage states with respect to the other used sensors. However, the observed sensitivity of the other sensors becomes comparatively high in the peak values of the root mean square deviation index.

• Convergence Security Journal
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• v.14 no.6_2
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• pp.83-88
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• 2014

First investigation is urgent investigation activities to arrest and to obtain evidence at the beginning of the incident. If the first investigation is wrong, the crime will not be solved or a lot of evidence will be disappeared. Therefore, if the first investigation is wrong, Wasting a lot of manpower and budget, or the other victims are to occur. First investigation is the crime scene centered investigation, victim centered investigation and damaged goods centered investigation. The crime scene centered investigation is the investigation on the discovery of dropped objects, to confirm thd date of offense, on the discovery of witnesses. Victim centered investigation is the investigation of victim's personal information, the living conditions of the family, fellowship and home interior matter. Damaged goods centered investigation is the investigation on the place of crime damaged goods and the movement route of crime damaged goods. In order to reinforce the investigative capacity of police first investigation, It is needed to reinforce the education on the first investigation, to conduct continuously for FTX (field training), to product the manual for first investigation, to build a case analysis system, to develop of forensic techniques and the coordination of national. The police should be giving people faith from the first investigation.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.96-102
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• 2006

Because of the increasing need to use clayey soil as the backfill in reinforced soil structures and embankment material, nonwoven geotextiles with the drain capability have been receiving much attention. However, there are few studies of the deformation behavior of nonwoven geotextiles at geosynthetics reinforced soil structures in the field because the nonwoven geotextile, which has low tensile stiffness and higher deformability than geogrids and woven geotextiles, is difficult to measure its deformation by strain gauges and to prevent the water from infiltrating. This study proposes a new, more convenient method to measure the deformation behaviour of nonwoven geotextile by using a strain gauge; and examines the availability of the method by conducting laboratory tests and by applying it on two geosynthetics reinforced soil (GRS) walls in the field. A wide-width tensile test conducted under confining pressure of 7kPa showed that the local deformation of nonwoven geotextile measured with strain gauges has a similar pattern to the total deformation measured with LVDT. In the field GRS walls, nonwoven geotextile showed a larger deformation range than the woven geotextile and geogrid; however, the deformation patterns of these three reinforcement materials were similar. The function of strain gauges attached to nonwoven geotextile in the walls works normally for 16 months. Therefore, the method proposed in this study for measuring nonwoven geotextile deformation by using a strain gauge proved useful.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.367-372
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• 2006

Government is not only the biggest owner in public sector, but also the leader responsible for improving and fostering construction industry. Delivery systems and award methods are enacted as laws via government's strong will for construction innovation. In addition to establishing relationships between government and contractor, delivery systems and award methods affect every aspect of industry. Therefore, the government should keep trying to remove inefficiency and achieve Best Value. This paper analyzes the delivery systems and award methods of advanced countries to extract lessons for Korean industry focusing on leading parties, direction, and change in owner's awareness of their respective innovative movements for construction. The prerequisites for improvement in delivery systems and award methods are suggested as partnership between public and private sectors, consistent innovation, enhancement in efficiency, and reinforcement of owner's capability.