• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.95-105
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• 2020

In order to promote efficient coastal management, it is important to continuously monitor the characteristics of the terrain, which are changed by various factors. In this study, time series UAV images were taken of Gyeokpo beach. And the standard deviation of ±11cm(X), ±10cm(Y), and ±15cm(Z) was obtained as a result of comparing with the VRS measurement performance for UAV position accuracy evaluation. Therefore, it was confirmed that the tolerance of the digital map work rule was satisfied. In addition, as a result of monitoring the erosion and sedimentation changes using the DSM(digital surface model) constructed through UAV images, an average of 0.01 m deposition occurred between June 2018 and December 2018, and in December 2018 and June 2019. It was analyzed that 0.03m of erosion occurred. Therefore, 0.02m of erosion occurred between June 2018 and June 2019. From the topographical change analysis results, the area of erosion and sediment height was analyzed, and the area of erosion and sedimentation was widely distributed in the ±0.5m section. If we continuously monitor the topographical changes in the coastal regions by using the 3D terrain modeling results using the time series UAV images presented in this study, we can support the coastal management tasks such as supplement or dredging of sand.

• Journal of Korea Port Economic Association
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• v.24 no.1
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• pp.61-83
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• 2008

The meaning of "added value" refers to the contribution of the factors of production, i.e., land, labor, and capital goods, to raising the value of a product and corresponds to the incomes received by the owners of these factors. The importance of added value in service industry has been recognized as one of the critical factors to economic growth, even in logistics industry. But, it is hard to find out the previous studies providing a clear definition and framework for designing and analyzing the performance of Value Added Logistics(VAL). The purpose of this study is to define the meaning of extended VAL that extensively includes activities initiating and operating the reverse logistics under the closed-loop logistic scheme, and to suggest the framework that describes the partnerships among participants involving in operating the value added logistics. Also, in this paper, we emphasize on the need for investigation of added value logistics definition and framework based on previous academic studies, and examine various value added logistics service activities of current leading 3PL companies across the world. Finally, we suggest the analytic framework for value added logistics throughout closed-loop logistics.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.55-64
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• 2017

In this paper, we propose and implement an IoT based mobile smart monitoring system in the view point of safety inspection for solar power generation. The main features and contributions of proposed system are as follows. First, the proposed system model can evaluate periodically in the view point of safety inspection the conditions of the system and structure of solar power generation. Second, the proposed system automatically re-processes the measurement data of the system and structure for solar power generation and save it into database. Third, using the re-processed and saved information, the proposed system can provide the monitoring information with webpage form to both administrator and owner of solar power generation system, thus they can measure and confirm directly in the view point of safety inspection the conditions of the solar generation structure without visiting those places. Fourth, the provided web pages for the monitoring of solar power generation can be accessed regardless of the system structures. The performance evaluations of the proposed system show that the proposed monitoring system can save efficiently the data received from the sensors installed in the structure of solar power generation into the data base in the collecting server. And the proposed system can support that both administrator and user of solar power generation system access webpage in real time without considering places by using mobile phone and desktop computer and obtain the information for the conditions of the system and structure of solar power generation with graph forms.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.1
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• pp.67-82
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• 2009

This paper examines the regional economic development policies of the Welsh Development Agency for attracting companies from the perspective of industrial location theory. The Welsh Development Agency has succeeded in attracting domestic or international capital, as a core actor for the regional economic development, and responded to the changing business environment and to the specific and various needs of the investors. The analysis of the Welsh case provides an important theoretical and practical implications. First, the Welsh case shows the importance of the role of the public sectors for the regional economic development. As the behavioral approach and the industrial location theory argue, the attraction of domestic or international capital led to the regional economic development. Second, the effective activities for attracting capital played an important role in the development. The quality and quantity of the information, in the industrial location theory, and the capacity of the business groups, in the behavioral approach, are significant factors of the development. Third, incentives by the Agency are also important. This finding not only supports the classical location model based on the cost and profits, but also the behavioral approach. Finally, the Welsh case could not succeeded in gaining regional economic competitiveness, even though attracting companies, by disregarding the industrial specialization strategy at the local level. This implies that we need to build industrial clusters. In sum, the behavioral approach has significant implications to the understanding of the public policies for attracting companies.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.505-512
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• 2016

Even though high performance concrete was developed according to the trend of bigger and higher of reinforced concrete building, the rheological evaluations such as viscosity, yield stress are not enough to use as input data to accomplish the numerical analysis for the construction design. So there are many problems in the harden concrete such as poor compaction, rock pocket and crack, etc. in the field. In this study, consistency curves were measured by the viscometer as hydration reaction time passed. At the same time the slump flow test and Vicat setting test were carried out for comparing with the results of rheological properties. The fluidity of the W/B 30% decreased as the increase of replacement ratio of blast furnace slag. But in case of W/B 40%, the replacement ration did not significantly influenced to the slump flow value with the passage of hydration time. By the replacement of blast furnace slag to cement, initial setting was delayed and the time gap between initial and final setting became shorten. Through the regression analysis using Bingham model, there are a sudden changes of viscosity and yield stress around initial setting in case of low W/B 30%. The increase of workability by the change of free water in cement paste was offset by the coating effect of impermeable layer in case of W/B 40%.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.86-94
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• 2020

Purpose: The purpose of this study is to compare the volume stability depending on the mixing methods and storage time for the conventional alginate and extended-pour alginate. Materials and methods: An arch-shaped metal model was fabricated, and one conventional alginate and two extended-pour alginates were used to take impressions using different mixing methods (hand and automatic). 120 impressions were taken (40 per each alginate) and stone models were made in accordance with the different storage times (immediate, 2 days, 5 days, and 6 days). The models were scanned with a 3D table scanner and dimensional change was measured by superimposing the scan data. Using SAS 9.4 (SAS Institute Inc., Cary, NC, USA), the general linear model and Tukey's post hoc test was conducted for statistical analysis (P<.001). Results: There was no statistically significant difference in the dimensional accuracy between two mixing methods, and the volume change was minimum when the stone was poured immediately in all groups. Dimensional accuracy showed a statistically significant difference between groups after 2 days of storage, and extended-pour alginate showed higher accuracy after 5 days of storage comparing to conventional one. Large amounts of volume change were showed at 2 - 5 days for conventional alginate and at 5 - 6 days for extended pour alginate. Conclusion: The mixing method of alginate does not affect volume stability. Although extended-pour alginate has better volume stability than conventional alginate for a long time, it is recommended to pour stone as soon as possible.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.6
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• pp.17-24
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• 2002

Dynamic behaviors of a bridge system with several simple spans are evaluated to examine the effects of nonlinear abutment motions upon the seismic responses of the bridge. The idealized mechanical model for the whole bridge system is developed by adopting the multi-degree-of-freedom system, which can consider various influential components. To compare the results, both linear and nonlinear abutment-backfill models are prepared. The linear system has the constant abutment stiffness, and the nonlinear system has the nonlinear stiffness considering the abutment stiffness degradation due to the abutment-soil interaction. From simulation results, the nonlinear abutment motion is found to have an important influence upon the global bridge motions. Maximum relative distances between adjacent vibration units are found to be larger than those found from the linear system. In particular, maximum relative distances at the location with the highest possibility of unseating failure are increased up to about 30% in the nonlinear system. The effects of nonlinear behavior of an abutment on the bridge seismic behaviors are also increased as the number of span increase. Therefore, it can be concluded that the abutment-soil interaction should be considered in the seismic analysis of the bridge system.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.377-382
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• 2020

A sequential design of experiments was employed to optimize MOF-235 synthesis for acetylene adsorption process. Two experimental designs were applied: a two-level factorial design for screening and a central composite design, one of response surface methodologies (RSM). In this study, 2³ factorial design of experiment was used to evaluate the effect of parameters of synthesis temperature and time, and also mixing speed on crystallinity of MOF-235. Experiments were conducted 16 times follwing MINITAB 19 design software for MOF-235 synthesis. Half-normal, pareto, residual, main and interaction effects were drawn based on the XRD results. The analysis of variance (ANOVA) of test results depicts that the synthesis temperature and time have significant effects on the crystallinity of MOF-235 (response variable). After screening, a central composite design was performed to optimize the acetylene adsorption capacity of MOF-235 based on synthesis conditions. From nine runs designed by MINITAB 19, the result was calculated using the second order model equation. It was estimated that the maximum adsorption capacity (18.7 mmol/g) was observed for MOF-235 synthesized at optimum conditions of 86.3 ℃ and 28.7 h.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.1-18
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• 2009

A series of three-dimensional numerical simulations using a generalized multidimensional hydrodynamic dispersion numerical model is performed to simulate effectively and to evaluate quantitatively impacts of urbanization on density-dependent groundwater flow and salt transport in a coastal aquifer system, Suyeong-Gu, Busan, Korea. A series of steady-state numerical simulations of groundwater flow and salt transport before urbanization with material properties of geologic formations, which are established by numerical modeling calibrations considering all the urbanization factors, is performed first without considering all the urbanization factors. A series of transient-state numerical simulations of groundwater flow and salt transport after urbanization is then performed considering the urbanization factors individually and all together. Finally, the results of both numerical simulations are compared with each other and analyzed. The results of the numerical simulations show that density-dependent groundwater flow, salt transport, and seawater intrusion in the coastal aquifer system are intensively and extensively impacted by the urbanization factors. Especially, these urbanization factors result in the changes of the total groundwater volume and salt mass in the coastal aquifer system. However, such impacts of each urbanization factor are not spatially uniform but locally different.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.336-342
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• 2002

Background: Recently, cell transplantation has been extensively investigated to improve heart function in dysfunctional heart. This study was designed to compare the effects of smooth muscle cells (SMC) and heart cells (HC) transplantation in dilated cardiomyopathic hamsters. Material and Method: HC and SMC were isolated from heart and ductus deferens of BIO 53.58 hamsters, and cultured for transplantation. HC and SMC or culture medium were transplanted into the left ventricle of 17 weeks old adult hamsters in HC transplanted (HCTx), SMC transplantation (SMCTX), and control groups (Con) (N = 10 each). Cyclosporine (5 mg/Kg) was administered subcutaneously for HCTx. Sham operated hamsters (N=10) underwent the surgery but did not receive an injection. At 4 weeks after transplantation, heart function was evaluated in all groups using a Langendorff perfusion apparatus. Result: Histology showed severe focal myocardial necrosis in all groups. HCTx and SMCTx formed huge muscle tissue in dilated myocardium. SMCTx and HCTx had better heart function than Con and sham (p<0.01). And SMCTx had better peak systolic pressure (p<0.05) antral developed pressure (p<0.05) than HCTx. But sham and Con did not any statistical make difference. Conclusion: SMCTx and HCTx formed muscle tissue and improved ventricular function in hamsters with dilated cardiomyopathy And SMCTx showed better heart function in peak systolic pressure and developed pressure than HCTx.