• Journal of the Korean Society for Nondestructive Testing
• /
• v.32 no.4
• /
• pp.393-400
• /
• 2012

In recent years, nano-structured thin film systems are often applied in industries such as MEMS/NEMS device, optical coating, semiconductor or like this. Thin films are used for many and varied purpose to provide resistance to abrasion, erosion, corrosion, or high temperature oxidation and also to provide special magnetic or dielectric properties. Quite a number of articles to evaluate the characterization of thin film structure such as film density, film grain size, film elastic properties, and film/substrate interface condition were reported. Among them, the evaluation of film adhesive to substrate has been of great interest. In this study, we fabricated the polymeric thin film system with different adhesive conditions to evaluate the adhesive condition of the thin film. The nano-structured thin film system was fabricated by spin coating method. And then V(z) curve technique was applied to evaluate adhesive condition of the interface by measuring the surface acoustic wave(SAW) velocity by scanning acoustic microscope(SAM). Furthermore, a nano-scratch technique was applied to the systems to obtain correlations between the velocity of the SAW propagating within the system including the interface and the shear adhesive force. The results show a good correlation between the SAW velocities measured by acoustic spectroscope and the critical load measured by the nano-scratch test. Consequently, V(z) curve method showed potentials for characterizing the adhesive conditions at the interface by acoustic microscope.

• Journal of Korean Society of Steel Construction
• /
• v.23 no.1
• /
• pp.99-111
• /
• 2011

This paper presents an investigation of the structural stability of cable-stayed bridges in the construction stage, using geometric nonlinear finite-element analysis and considering various geometric nonlinearities, such as the sag effect of the cables, the P-${\Delta}$ effects of the girder and mast, and the large displacement effect. Initial shape analysis and construction-stage analysis were performed to determine the equilibrium of the structure in the construction stage. After that, geometric nonlinear analysis was performed to study structural stability. In this study, the weight of the derrick crane and the key segment were considered the main external loads, which were applied to the tip of the center span. The cable arrangement type and the stiffness ratios of the girder and mast were considered the main parameters of the analytic research. Based on the results of the analysis, the change in the buckling mode and critical load factors with respect to the cable arrangement type and the stiffness ratios of the girder and mast was investigated. The buckling modes of the steel cable-stayed bridges in the construction stage were classified, and the ranges of the stiffness ratios of the girder and mast, which show these classified buckling modes, were suggested.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.2
• /
• pp.175-180
• /
• 1992

The occurrence of internal cavity of in red ginseng is one of critical quality criteria. The occurrence of internal cavity mainly due to fresh ginseng character that is determined by growth conditions. Growth conditions and percent occurrence of internal cavity were investigated on various ginseng plantations for 6 years and the relation. ships among them were statistically analysed. In addition, field experiments were carried out seperately for the effect of special factors. 1. Internal cavity in red ginseng mainly occurred on area between central part and cortex part of tap root in red ginseng. It was suppose to be caused by characteristics of fresh ginseng. 2. Soil moisture decreased percent occurrence of internal cavity(PIC) above 27.5 % of PIC and increased below it. 3. The factors of shade structure with high intensity of light condition tend to increase PIC. PIC was decreased below 15.9 % of light transmittance rate and increased above it.

• Korean Journal of Social Welfare
• /
• v.57 no.2
• /
• pp.143-164
• /
• 2005

The study is to analyze support-related issues, particularly associated with elderly and children care, which have been a fundamental agenda of family welfare policy. We are expected for societal-level controversy on the relationship of family support and social security in the near future because of rapid increase in ageing and divorce rate. Accordingly, we need to establish social consensus on the extent to which both family support system and social support system are responsible for the life maintenance of the elderly and the children from divorced family. We also clarify the various characteristics(including scope, degree, period of time, and need/manageability) of support provided by family members. Considering the changes of family structure and population composition, the policy of supporting the old and children should go for social responsibility. Findings show that civil law and social welfare law have unclear application on the relationship between family support and social security, and contents in family support. In particular, public assistance law strongly emphasizes the principle of family support while social insurance laws provide only limited and insufficient family maintenance. The suggestions of further study on support-related issues are given in the rapidly changing society and the increasing economic instability.

• Journal of The Korean Association For Science Education
• /
• v.33 no.4
• /
• pp.751-762
• /
• 2013

The purpose of the study is to develop a science writing program for middle school students and to analyze the effects of this program. The program consists of twenty-one 10-minute long sessions in 2 chapters (stimulus and response; the structure and function of plants) from the $2^{nd}$ year middle school textbooks. The team selected themes in science writing that can cultivate multiple facets of creativity in students: flexibility, originality and elaboration. The format of the science writing was diverse. The program was conducted through worksheets, and there was separate section within the worksheet for teacher to give feedback to students. The science writing program with teacher's feedback improved students' scientific creativity(p<.01). It seems like teacher's feedback is critical in checking students' concept and boosting students' creativity. The program is statistically effective in improving students' flexibility(p<.01), however it is not the case for improving on their originality and ability to elaborate(p>.05). We assumed that the relatively extensive portion of the writing was not suitable to improve students' ability to elaborate their ideas further as well as fostering originality. In order to improve the students' creativity and ability to elaborate, there is a need to adjust the amount of science writing, content, time.

• Fisheries and Aquatic Sciences
• /
• v.13 no.2
• /
• pp.167-181
• /
• 2010

To predict changes in the marine environment of the Beolgyo Stream Estuary in Jeonnam Province, South Korea, where cohesive tidal flats cover a broad area and a large bridge is under construction, this study conducted numerical simulations involving tidal flow and cohesive sediment transport. A wetting and drying (WAD) technique for tidal flats from the Princeton Ocean Model (POM) was applied to a large-scale-grid hydrodynamic module capable of evaluating the flow resistance of structures. Derivation of the eddy viscosity coefficient for wakes created by structures was accomplished through the explicit use of shear velocity and Chezy's average velocity. Furthermore, various field observations, including of tide, tidal flow, suspended sediment concentrations, bottom sediments, and water depth, were performed to verify the model and obtain input data for it. In particular, geologic parameters related to the evaluation of settling velocity and critical shear stresses for erosion and deposition were observed, and numerical tests for the representation of suspended sediment concentrations were performed to determine proper values for the empirical coefficients in the sediment transport module. According to the simulation results, the velocity variation was particularly prominent around the piers in the tidal channel. Erosion occurred mainly along the tidal channels near the piers, where bridge structures reduced the flow cross section, creating strong flow. In contrast, in the rear area of the structure, where the flow was relatively weak due to the formation of eddies, deposition and moderated erosion were predicted. In estuaries and coastal waters, changes in the flow environment caused by artificial structures can produce changes in the sedimentary environment, which in turn can affect the local marine ecosystem. The numerical model proposed in this study will enable systematic prediction of changes to flow and sedimentary environments caused by the construction of artificial structures.

• The Journal of the Korea Contents Association
• /
• v.16 no.1
• /
• pp.445-458
• /
• 2016

The purpose of this study is to develop indicators for assessing korean youth lifelong learning competency and to validate the structure of the competencies. To achieve this research aims, the indicators for assessing life-long learning competence were drawn by systemic literature review and they were validated and modified by expert review method and two surveys targeting youth. 28 youth experts participated in the expert review. Participants were 333 middle or high school students for the first survey and 791 middle or high school students for the second survey. As results, the 3 competencies and nine sub-competencies were developed: thinking(wholistic thinking, critical thinking, emotional thinking), intellectual tools use(language, mathematic and science, information and communication technology), learning adaptability(change capacity, intellectual curiosity, learning-direction). The results of this study will provide the fundamental guidelines for developing various activities and establishing youth policies related to korean youth life-long learning competency.

• Macromolecular Research
• /
• v.13 no.3
• /
• pp.167-175
• /
• 2005

This review explores recent works involving the use of the self-assembled nanoparticles of bile acid-modified glycol chitosans (BGCs) as a new drug carrier for cancer therapy. BGC nanoparticles were produced by chemically grafting different bile acids through the use of l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). The precise control of the size, structure, and hydrophobicity of the various BGC nanoparticles could be achieved by grafting different amounts of bile acids. The BGC nanoparticles so produced formed nanoparticles ranging in size from 210 to 850 nm in phosphate-buffered saline (PBS, pH=7.4), which exhibited substantially lower critical aggregation concentrations (0.038-0.260 mg/mL) than those of other low-molecular-weight surfactants, indicating that they possess high thermodynamic stability. The SOC nanoparticles could encapsulate small molecular peptides and hydrophobic anticancer drugs with a high loading efficiency and release them in a sustained manner. This review also highlights the biodistribution of the BGC nanoparticles, in order to demonstrate their accumulation in the tumor tissue, by utilizing the enhanced permeability and retention (EPR) effect. The different approaches used to optimize the delivery of drugs to treat cancer are also described in the last section.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.1B
• /
• pp.101-110
• /
• 2011

With the deployment of broadband networking technology, many clients are enabled to receive various Video on Demand (VoD) services. To support many clients, the network should be designed by considering the following factors: viewer's waiting time, buffer requirement at each client, number of channel required for video delivery, and video segmentation complexity. Among the currently available VoD service approaches, the Polyharmonic and Staircase broadcasting approaches show best performance with respect to each viewer's waiting time and buffer requirement, respectively. However, these approaches have the problem of dividing a video into too many segments, which causes very many channels to be managed and used at a time. To overcome this problem, we propose Polyharmonic-Staircase-Staggered (PSS) broadcasting approach that uses the Polyharmonic and Staircase approaches for the head part transmission and the Staggered approach for the tail part transmission. It is simple and bandwidth efficient. The numerical results demonstrate that our approach shows viewer's waiting time is comparable to that in the Harmonic approach with a slight increase in the bandwidth requirement, and saves the buffer requirement by about 60\% compared to the Harmonic broadcasting approach by simply adjusting the video partitioning coefficient factor. More importantly, our approach shows the best performance in terms of the number of segments and the number of channels managed and used simultaneously, which is a critical factor in real operation of VoD services. Lastly, we present how to configure the system adaptively according to the video partitioning coefficient.

• Cartoon and Animation Studies
• /
• s.18
• /
• pp.17-35
• /
• 2010

The purpose of this study is to find out the way to improve the funding system of Korean animation, which will lead the establishment of virtuous circle of Korean animation industry. The funding structure of Korean animations in the period of 2005-2009 is analyzed to find out that the funding surveyed to find out that the domestic funding source for Korean animation has reached its limitation. Without any active involvement of public fund, this will result in the shrink of Korean animation industry with heavy reliance on foreign capital and limited quality of Korean animation. This is not only a serious problem of Korean animation industry, but also the problem of Korean cultural identity and variety because it is related with the diminish and degradation of Korean children and family content. Meanwhile, in France and Canada, which are the major co-production partners of Korean animation, the animation production is being activated by the full support of government fund system, because the animation is regarded as the important genre which plays a critical public role in establishing the cultural identity and variety of such countries. Improvement of Korean animation funding system is not pursued by more injection of public fund into the industry. It should be designed to facilitate the investment from the private sector by improving the profitability of Korean animation. This goal can be achieved by public fund with annual budget of 25 billion Korean Won supporting the distribution and production of Korean animation. Discussion should be needed for securing the funding resources such as establishment of new animation fund or utilization of existing fund.