• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.76-82
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• 2019

This study has done to search for a solution to remove risk limitedly caused by separating weapon system acquisition from operation and maintenance at the view point of Logistic Commander who's responsible for stable operation and maintenance after acquiring weapon system. At the System development stage, unverified overhaul development plan may cause additional manpower and costs after the development, and furthermore it is likely to have risk to lower reliability of the military. Thus, research and development agency should write overhaul development plan at the System development stage, and it should be verified through evaluation and verification test. Secondly, during research and development, institutional supplementation is needed to calculate human and material resources writing overhaul development plan. Thirdly, it should be able to analyze proper operation & maintenance plan and cost for overhaul plan at the pre-investigation stage. Fourthly, the base which can develop overhaul concept and overhaul factors should be included in the need and need determination document. Lastly, for the weapon system which has small amount of high power figure, project management should be performed to be able to specify at the each acquisition level of weapon system to realize Article 28, clause 3 and 4 of Defense business law.

• Korean Journal of Remote Sensing
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• v.34 no.6_2
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• pp.1273-1282
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• 2018

Recently, active research on the Arctic Ocean has been conducted due to the influence of global warming and new Arctic ship route. Although previous studies already calculated quantitative extent of sea ice using passive microwave radiometers, melting at the edge of sea ice and surface roughness were hardly considered due to low spatial resolution. Since Sentienl-1A/B data in Extended Wide (EW) mode are being distributed as free of charge and bulk data for Arctic sea can be generated during a short period, the entire Arctic sea ice data can be covered in high spatial resolution by mosaicking bulk data. However, Sentinel-1A/B data in EW mode, especially in HV polarization, needs significant radiometric correction for further classification. Thus, in this study, we developed algorithms that can correct thermal noise and scalloping effects, and confirmed that Arctic sea ice and open-water were well classified using the corrected dual-polarization SAR data.

• Journal of Technology Innovation
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• v.27 no.1
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• pp.45-77
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• 2019

The balance between exploration for new possibility and exploitation for existing certainty is an important issue in strategy, innovation, R&D as well as organization learning. Among the convergence trends of technologies, many firms seek to have the wider technological knowledge assets and the deeper technology capabilities for the sustainable competitive advantage at the same time. While firms plan technology portfolio strategies, they should consider the attribute of the technology. Nanotechnology, a cutting-edge technology, is a general purpose technology, unlike conventional product-oriented technologies. This empirical study was focused on how multi-national firms' exploration and exploitation strategies for nanotechnology affect their innovative and financial performance. It uses multiple regression analysis on panel data. This result shows that the more diversified and specialized nanotechnology as platform technology is positively related to their innovative and financial performance, unlike the research results for product-oriented technologies. In addition, exploratory innovation is more effective to firm performance than exploitation. This implies how global firms can manage effectively platform technology strategies under the constraints of resources.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.434-445
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• 2020

In this study, the minimization of harbor oscillation using permeable breakwater was applied to the actual harbor and investigated an effect of minimization by computer simulation in order to take into account the water quality problems and measures of harbor oscillation by infragravity waves at the same time. The study site is Mukho harbor located at East coast of Korea that harbor oscillation has been occurred frequently. The infragravity waves obtained by analyzing the observed field data for five years focused on the distribution between wave periods of 40 s and 70 s and wave heights in less than 0.1 m was 94% of analyzing data. The target wave periods was 68.0 s. The most effective method of minimization of harbor oscillation by infragravity waves was to install a detached permeable breakwater with transmission coefficient of 0.3 on the outside harbor and replace some area of the vertical wall in the harbor with wave energy dissipating structure to achieve a reflectivity of 0.9 or less. The amplitude reduction rate of this method shown in 27.4%. And the effect of the difference in transmission coefficient of permeable breakwater on the reduction rate of the amplitude was not significant.

• Journal of Korean Medicine for Obesity Research
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• v.20 no.2
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• pp.69-77
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• 2020

Objectives: In this study, we investigated the antiobesity and antidiabetic effects of polyherbal extract, DM2 consisting of Atractylodis Rhizoma, Anemarrhenae Rhizoma, Cinnamomi Cortex, and Moutan Radicles Cortex in high fat diet-induced obesity mice. Methods: DM2 extract was prepared with a hot water. Six-week-old male C57BL/6N mice were fed a high-fat diet (HFD) for 8 weeks and then administrated with DM2 extract (500 mg/kg, p.o.) for 4 weeks. The changes of physiological markers, body weight (BW), food and water intakes, and the levels of fasting blood glucose (FBG) were measured once a week for 4 weeks in mice. The the serum levels of glucose, insulin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (T-CHO), triglyceride, and low density lipoprotein cholesterol in sera were measured in mice using autometic chemical analyzer and enzyme linked immunosorbant assay. We also observed the histological changes of liver and pancreatic tissues with Hematoxylin & Eosin staining. Results: In physiological change, the increases of BW, calorie intake, and FBG in HFD-induced obese mice were significantly decreased after administration of DM2 extract for 4 weeks. The decrease of water intake was significantly increased in DM2 extract-administrated mice. In serological change, the administration of DM2 extract in obesity mice was significantly decreased the serum levels of glucose, insulin, T-CHO, AST, and ALT levels. We also found that DM2 extract inhibited the increase of lipid droplets in liver and the structural destruction of pancreatic tissues in obesity mice. Conclusion: Our study demonstrated that DM2 extract has antiobesity antidiabetic effects with body weight loss, decrease of glucose and insulin levels, and lipid accumulation on liver tissue.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1435-1447
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• 2020

The seasonal variations in weather parameters can significantly affect the atmospheric transmission characteristics. Herein, we propose a novel augmented multiple regression algorithm for the accurate estimation of atmospheric transmittance and solar irradiance over highly localized areas. The algorithm employs 1) adaptive atmospheric model selection using measured meteorological data and 2) multiple linear regression computation augmented with the conventional application of MODerate resolution atmospheric TRANsmission (MODTRAN). In this study, the proposed algorithm was employed to estimate the solar irradiance over Taean coastal area using the 2018 clear days' meteorological data of the area, and the results were compared with the measurement data. The difference between the measured and computed solar irradiance significantly improved from 89.27 ± 48.08σ W/㎡ (with standard MODTRAN) to 21.35 ± 16.54σ W/㎡ (with augmented multiple regression algorithm). The novel method proposed herein can be a useful tool for the accurate estimation of solar irradiance and atmospheric transmission characteristics of highly localized areas with various weather conditions; it can also be used to correct remotely sensed atmospheric data of such areas.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.308-320
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• 2021

An integrated sediment management approach that includes the recovery of the amount of declined sediment supply is effective as a fundamental solution to coastal erosion. During planning, it is essential to analyze the transfer mechanism of the sediments generated from estuaries (the junction between a river and sea) to assess the amount and rate of sediment discharge (from the river to sea) supplied back to the coast. Although numerical models that interpret the tidal sand bar flushing process during flooding have been studied, thus far, there has been no study focusing on the formation and development processes of tidal sand bars. Therefore, this study aims to construct wave deformation, flow regime calculation, and topographic change analysis models to assess the amount of recovered sediment discharge and reproduce the tidal sand bar formation process through numerical analysis for integrated littoral drift management. The tidal sand bar formation process was simulated, and the wave energy and duration of action concepts were implemented to predict the long-term littoral movement. The river flux and wave conditions during winter when tidal sand bars dominantly develop were considered as the external force conditions required for calculation. The initial condition of the topographic data directly after the Maeupcheon tidal sand bar flushing during flooding was set as the initial topography. Consequently, the tidal sand bar formation and development due to nearshore currents dependent on the incident wave direction were reproduced. Approximately 66 h after the initial topography, a sand bar formation was observed at the Maengbang estuary.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.1
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• pp.14-22
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• 2022

The purpose of this study is to provide evidence for discovering functional materials through the anti-inflammatory efficacy screening of randomly selected medicinal herbs. We prepared 70% ethanol extracts from 10 herbs and evaluated for the inhibitory effect of NO production on LPS-stimulated mouse macrophage cell line Raw 264.7. As a result, it was confirmed that the Chrysanthemi Zawadskii Herba (CZ) extract had the highest effect of inhibiting NO production induced by LPS. We therefore measured and compared NO inhibitory effects at different concentrations (10, 50, 250 ㎍/mL) of 70% ethanol and water extract of CZ. It was observed that both ethanol and water treatment groups inhibited NO production in a concentration-dependent manner in both ethanol and water treatment groups. In particular, it was confirmed that the CZ 70% ethanol extract (99.97%) had a higher NO inhibitory effect than the water extract (93.32%) in the high concentration (250 ㎍/mL) treatment group. There was no effect of CZ extract on cell viability at all concentrations used in the experiment. Moreover, it was shown that CZ ethanol extract remarkably inhibited the expression of VCAM-1 induced by TNF-𝛼, and it was slightly decreased even by treatment with water extract. This study suggests that Chrysanthemi Zawadskii Herba has potential as a functional substance that regulates vascular inflammation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.315-324
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• 2022

The experimental data obtained in a wave flume were analyzed using machine learning techniques to establish a model that predicts the input wave height of the wavemaker based on the waves that have experienced wave shoaling and to verify the performance of the established model. For this purpose, artificial neural network (NN), the most representative machine learning technique, and Gaussian process regression (GPR), one of the non-parametric regression analysis methods, were applied respectively. Then, the predictive performance of the two models was compared. The analysis was performed independently for the case of using all the data at once and for the case by classifying the data with a criterion related to the occurrence of wave breaking. When the data were not classified, the error between the input wave height at the wavemaker and the measured value was relatively large for both the NN and GPR models. On the other hand, if the data were divided into non-breaking and breaking conditions, the accuracy of predicting the input wave height was greatly improved. Among the two models, the overall performance of the GPR model was better than that of the NN model.

• Journal of Korean Medicine for Obesity Research
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• v.22 no.2
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• pp.102-114
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• 2022

Objectives: We investigated the effects of Allii Fistulosi Bulbus (AFB) on high fat diet (HFD)-induced obesity in mice and the regulation of energy metabolism in muscle tissues of mice. Methods: The C57BL/6 mice (6 weeks, male) were fed a HFD for 8 weeks and then administrated with AFB extract at 500 mg/kg (p.o.) once daily for 4 weeks. The body weight (BW), muscle weight, calorie intake, fasting blood glucose (FBG) and serum glucose, insulin, and low-density lipoprotein-cholesterol (LDL-C) levels were measured in mice. It was also observed the histological changes of pancreas, liver, and fat tissues with hematoxylin and eosin staining. It was investigated the phosphorylation of insulin receptor substrate 1 (IRS-1), Ser/Thr kinase (AKT), and adenosine monophosphate-activated protein kinase (AMPK), and the expression of phosphoinositide 3-kinase, glucose transporter type 4 (GLUT4), and sirtuin1 (Sirt1) in gastrocnemius tissues by western blot, respectively. Results: The increases of BWs, calorie intakes and FBG levels in obesity mice were decreased significantly by the administration of AFB extract. The AFB extract administration was reduced significantly serum levels of glucose, insulin, and LDL-C in obesity mice. The AFB extract inhibited lipid accumulation in liver tissues, hyperplasia of pancreatic islets, and enlargement of fat tissues in obesity mice. The phosphorylation of IRS-1 and AKT was increased significantly in muscle tissues and AMPK phosphorylation and the GLUT4 and Sirt1 expression were decreased significantly in muscle tissues after the AFB administration. Conclusions: Our study indicates that AFB extract improves symptoms of obesity through regulation of energy regulating proteins in muscle tissues.