• The Journal of Fisheries Business Administration
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• v.33 no.2
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• pp.1-29
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• 2002

The main objective of this research aims at analyzing efficiency of government financial transfers(GFTs) to the Korean fisheries sector, using the Linear Structural Relations model(i.e., LISERL model) and the field survey data. Most policies of GFTs tend to be implemented to protect industries with weak competitive advantages such as infant and/or primary industries. Specific policy instruments include income transfers, government loans with lower interest rates, taxes and the like. Fishing activities are made at a highly changeable natural environment of the ocean with a great amount of risk and uncertainty. Fishing households make their livelihood under the small-scale fisheries. Such fisheries and fishing households have also a relatively weak market power. Because of these fisheries characteristics most coastal states have adopted a variety of government support programs. However, despite such a huge government support, during the past several decades the world fishing communities have seen a tendency of continuous fishereis resource overexploitation. For this resason there have been hot debates over the government support policies for fisheries through OECD, FAO, WTO, and UNEP. In general, policy evaluations tend to be made on the basis of benefit-cost(B/C) analysis. However, the B/C analysis may produce results quite different from real ones primarily due to many unmeasurable effects. Thus, the authors composed simple questionaires and let fishermen, government officials and academic people answer the questions. The survery was made in several ways such as post-mail and personal/group interviews. In recent years, for analysis of policy performances and effectiveness, the LISREL model has often been used, which consists of structural and measurement eqquations. This model has a good advantage of transforming unobservable variables to observable ones so that it helps construct endogenous cause and effect relationships among relevant variables. The evaluation was done from the two aspects: policy results and policy effectiveness. The policy result evaluation showed that there is a need for improvement for policy problem perception and decision-making process, while the policy effect evaluation suggested that the policy goals were successfully achieved and social justice was improved from the perspective of the entire society as well. However, the research results showed that the GFT policies rendered little contrubtion to narrowing down the gap between GFT beneficiaries and non-beneficiaries incomes.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.861-868
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• 2011

Flowmeters that measure the amount of fluid passing through conduits must kept accurate by comparison and the periodic calibration. The reference meters used are clamp-on meters that mount sensors on the outer wall of the pipe. They are called 1-path, 2-path or 4-path flowmeters depending on the number of sensors. We selected a flowmeter mainly used for K-water as test a flowmeter. We carried out experiments to find the intrinsic error of the flowmeter and errors in the downstream of a double bent pipe. The results show that there are the sensor locations that meet the tolerance. We suggested the angle of the sensor, the straight run from the downstream of the bent pipe and the number of sensors. So it is possible to improve the water treatment process and increase the accounted water rate by upgraded flow measurement technology.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.387-394
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• 2013

Data mining is the process of discovering hidden, non-trivial patterns in large amounts of data records in order to be used very effectively for analysis and forecasting. Because hundreds of variables give rise to a high level of redundancy and dimensionality with time complexity, they are more likely to have spurious relationships, and even the weakest relationships will be highly significant by any statistical test. Hence cluster analysis is a main task of data mining and is the task of grouping a set of objects in such a way that objects in the same group are more similar to each other than to those in other groups. In this paper system implementation is of great significance, which defines a new definition based on information-theoretic entropy and analyse the analogue behaviors of objects at hand so as to address the measurement of uncertainties in the classification of categorical data. The sources were taken from a survey aimed to identify of job guidance from students in high school pyeongtaek. we show how variable precision information-entropy based rough set can be used to group student in each section. It is proved that the proposed method has the more exact classification than the conventional in attributes more than 10 and that is more effective in job guidance for students.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.1
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• pp.70-78
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• 2000

In applying high-${\underline{T_c}}$ superconducting material to microwave devices, Uncertainty of electromagnetics of high-${\underline{T_c}}$ superconductor(HTS) and the temperature dependence of the substrate fits with HTS thin film cause difficulty in realization of such antenna for industrial applications. It must be noted to characteristic the HTS antenna in contrast with normal conducting counterpart for this real application. In this paper, a comparative study between HTS microstrip antennas and gold antennas was reported in terms of the return loss, the characteristic impedance, efficiency, and other various characteristics. HTS thin films were $YBa_2Cu_3O_{7-x}$ (YBCO) on MgO substrates. Superconducting microstrip antennas used in this work were to directly inset a microstrip transmission line into the 50 ${\Omega}$ region of the radiating patch. Measurement results of HTS antennas and gold antennas showed that usable antennas can be made using this architecture.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.8
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• pp.729-736
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• 2017

In this study, the physics-based model and machine learning technique were used to conduct model-assisted probability of detection (MAPOD) experiments. The possibility of using in-service cracked parts was also investigated. Bolt hole shaped specimens with fatigue crack on the hole surface were inspected using eddy current inspection. Owing to MAPOD, the number of experimental factors decreased significantly. The uncertainty in the crack length measurement for in-service cracked parts was considered by the application of Monte Carlo simulation.

• Fire Science and Engineering
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• v.31 no.5
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• pp.12-18
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• 2017

The present study has been conducted to predict the mass burning flux of methanol pool fire using liquid vaporization model in FDS and examine the effect of thermal properties of liquid fuel such as radiative fraction and mean absorption coefficient. A series of calculation for the pool diameter of 5 cm to 200 cm were performed and the size of computational domain was determined by the scale of the pool diameter. The reference grid size was determined by the grid sensitivity analysis and the computational grids consisted of approximately 750,000 cells. For the methanol pool fire, the mass burning flux predicted by liquid vaporization model of FDS followed the trend of transient characteristics as a function of pool diameter and showed good agreement within measurement uncertainty range of previous studies. The mass burning flux increased with increasing the radiative fraction and the mean absorption coefficient greatly affected on relatively small pool diameter.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1263-1268
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• 2018

Three different ice core samples from Antarctica were analyzed to identify activity concentrations of radioactive isotopes. Tracking migration of radioactive isotopes to Antarctica can provide a key clue to understand global environmental changes caused by radiation exposures because the Antarctic ice cores can preserve unique characteristics of various environmental conditions. We are particularly interested in the $^{137}Cs$ nucleus, because it is closely related to radiation exposure from nuclear power plant accidents and nuclear bomb tests. With its half life of $30.17{\pm}0.03$ years, $^{137}Cs$ can also be used to assess the age of sedimentation occurring after around the year 1945. We selected three ice core samples, called Tarn8, Styx27, and H25, from different time periods; the Tarn8 sample is known to be from earlier than ~ 1000 AD, the Styx27 sample is approximately from the year 1945, and the H25 sample is from the year 2012. Radioactive isotope measurements of the ice core samples were performed using a 100% HPGe detector at Cheongpyeong Underground Radiation Laboratory (CURL). We measured the activity of $^{137}Cs$ in the H25 sample to be $0.98{\pm}0.82mBq/kg$. Although the activity has a large uncertainty mainly due to the limited sample quantity, the $^{137}Cs$ isotopes in the Antarctic ice core were measured for the first time in Korea.

• Korean Journal of Remote Sensing
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• v.26 no.1
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• pp.29-38
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• 2010

It is necessary to develop an integration model which can account for various data acquired at different measurement scales in environmental thematic mapping with high-resolution ground survey data and relatively low-resolution remote sensing data. This paper presents and applies a multi-scale geostatistical methodology for downscaling of thematic maps generated from lowresolution remote sensing data. This methodology extends a traditional ordinary kriging system to a block kriging system which can account for both ground data and remote sensing data which can be regarded as point and block data, respectively. In addition, stochastic simulation based on block kriging is also applied to describe spatial uncertainty attached to the downscaling. Two downscaling experiments including SRTM DEM and MODIS Leaf Area Index (LAI) products were carried out to illustrate the applicability of the geostatistical methodology. Through the experiments, multi-scale geostatistics based on block kriging successfully generated relatively high-resolution thematic maps with reliable accuracy. Especially, it is expected that multiple realizations generated from simulation would be effectively used as input data for investigating the effects of uncertain input data on GIS model outputs.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.147-147
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• 2019

The Numerical Weather Prediction (NWP) models determine the future state of the weather by forcing current weather conditions into the atmospheric models. The NWP models approximate mathematically the physical dynamics by nonlinear differential equations; however these approximations include uncertainties. The errors of the NWP estimations can be related to the initial and boundary conditions and model parameterization. Development in the meteorological forecast models did not solve the issues related to the inevitable biases. In spite of the efforts to incorporate all sources of uncertainty into the forecast, and regardless of the methodologies applied to generate the forecast ensembles, they are still subject to errors and systematic biases. The statistical post-processing increases the accuracy of the forecast data by decreasing the errors. Error prediction of the NWP models which is updating the NWP model outputs or model output statistics is one of the ways to improve the model forecast. The regression methods (including linear, polynomial and scaling regression) are applied to the present study to improve the real time forecast skill. Such post-processing consists of two main steps. Firstly, regression is built between forecast and measurement, available during a certain training period, and secondly, the regression is applied to new forecasts. In this study, the WRF real-time forecast data, in comparison with the observed data, had systematic biases; the errors related to the NWP model forecasts were reflected in the underestimation of the meteorological data forecast by the WRF model. The promising results will indicate that the post-processing techniques applied in this study improved the meteorological forecast data provided by WRF model. A comparison between various bias correction methods will show the strength and weakness of the each methods.

• Nuclear Engineering and Technology
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• v.19 no.2
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• pp.107-114
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• 1987

Using a solution of $^{137}$ Cs as a tracer, radioactivity of a $^{137}$ Cs solution is measured by coincidence and anticoincidence counting methods. Sample sources in this study are fabricated by mixing $^{137}$ Cs with tracer, and the mixing ratios are 1/3 and 1/5, respectively in coincidence and anticoincidence methods. Specific activities of a $^{137}$ Cs solution are calculated by means of f-channel low energy threshold level variation and efficiency extrapolation. The results obtained by coincidence and anticoincidence counting methods are 552.78 kBq/g and 554.32kBq/g, respectively on the reference date and the combined uncertainties are 1.60kBq/g and 1.51kBq/g for each method. These two results show a good agreement within the uncertainty range.