• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.5
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• pp.237-243
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• 2014

In this paper, a calculation-efficient method for weight update in the algorithm based on maximization of the zero-error probability (MZEP) is proposed. This method is to utilize the current slope value in calculation of the next slope value, replacing the block processing that requires a summation operation in a sample time period. The simulation results shows that the proposed method yields the same performance as the original MZEP algorithm while significantly reducing the computational time and complexity with no need for a buffer for error samples. Also the proposed algorithm produces faster convergence speed than the algorithm that is based on the error-entropy minimization.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.51-51
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• 2023

최근 기후의 급격한 변화 및 이상기후로 인해 전 세계적으로 가뭄의 발생빈도가 증가하고 있는 추세이다. 우리나라의 경우 지역·계절별 강수량의 편차로 인해 국지적으로 극심한 가뭄이 발생하고 있으며, 향후 피해는 더욱 증가할 것으로 예측하고 있다. 농업가뭄은 농작물 생육에 따른 수확량 및 수자원 이용에 직접적인 영향을 미치고 있으며, 농업수리시설물의 의존도가 높기 때문에 저수지의 대응능력과 농경지의 수리답 시설이 농업가뭄 대응을 위한 중요한 지표로써 활용되고 있다. 본 연구에서는 수리시설물의 가뭄대응능력과 평야부 농경지의 가뭄빈도를 이용하여 농업가뭄 취약성 평가를 수행하였다. 2015년 이후 매년 가뭄이 발생하는 충청남도 태안군을 시범지역으로 선정하였으며, 논 중심의 농업가뭄을 평가하기 위해 기상영향, 가뭄발생현황, 보조수원능력, 가뭄대응능력 4가지의 관련 항목을 선정하였다. 기상영향, 가뭄발생현황, 보조수원현황 항목은 계수화를 위해 데이터 속성 정보만을 이용하여 가중치를 산정하는 엔트로피 (Entropy) 방법을 적용하였으며, 가뭄대응능력 항목은 농업수리시설물과 농경지 평균 가뭄빈도 분석을 통해 점수화를 수행하였다. 본 연구의 결과는 지역별로 선제적인 가뭄대응 우선순위를 결정할 수 있고, 용수공급의 효율화 등 논 중심의 농업가뭄 대응을 위한 기초자료로써 활용될 수 있을 것으로 판단된다.

• Korean Journal of Applied Biomechanics
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• v.29 no.4
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• pp.247-254
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• 2019

Objective: The goal of this study was to determine the center of pressure (CoP) complexity pattern in approximate entropy technique between genders at different conditions of running speed. Background: It is conducted to evaluate the complexity pattern of CoP in the increment of running speed to have insights to injury prediction, stability, and auxiliary aids for the foot. Method: Twenty men (age=22.3±1.5 yrs.; height=176.4±5.4 cm; body weight=73.9±8.2 kg) and Twenty women (age=20.8±1.2 yrs.; height=162.8±5.2 cm; body weight=55.0±6.3 kg) with heel strike pattern were recruited for the study. While they were running at 2.22, 3.33, 4.44 m/s speed on a treadmill (instrumented dual belt treadmills, USA) with a force plate, CoP data were collected for the 10 strides. The complexity pattern of the CoP was analyzed using the ApEn technique. Results: The ApEn of the medial-lateral and antero-posterior CoP in the increment of running speed showed significantly difference within genders (p<.05), but there were not statistically significant between genders at all conditions of running speed. Conclusion: Based on the results of this study, CoP complexity pattern in the increment of running speed was limited to be characterized between genders as an indicator to judge the potential injury and stability. Application: In future studies, it is needed to investigate the cause of change for complexity of CoP at various running speed related to this study.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.113-119
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• 2019

Objective: The purpose of this study was to investigate the effect of the falls on the center of pressure (CoP) complexity during gait using non-linear approximate entropy (ApEn). Method: 20 elderly women with experience of falling ($age=72.55{\pm}5.42yrs$; $height=154.40{\pm}4.26cm$; $body\;weight=57.40{\pm}6.21kg$; $preferred\;gait\;speed=0.52{\pm}0.17m/s$) and 20 elderly women with no experience of falling ($age=71.90{\pm}2.90yrs$; $height=155.28{\pm}4.73cm$; $body\;weight=56.70{\pm}5.241kg$; $preferred\;gait\;speed=0.56{\pm}0.13m/s$) were recruited for the study. While they were walking at their preferred gait speed on a treadmill (instrumented dual belt treadmills, Bertec, USA) with a force plate CoP data were collected for the 20 strides. The complexity of the CoP was analyzed using the ApEn technique. Results: The ApEn of the medial-lateral CoP in the fallers showed smaller about 16% compared to the non-fallers (p<.05). The ApEn of the antero-posterior CoP of the fallers showed smaller about 12% compared to the non-fallers, but the difference was not statistically significant. Conclusion: Based on the results of this study, the reduction of the medio-lateral CoP complexity in the elderly gait would be an index to determine the potential fall.

• Corrosion Science and Technology
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• v.21 no.5
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• pp.381-389
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• 2022

Cyclic Voltammetry and weight loss measurements were used to investigate corrosion prevention of tin in a 0.5M citric acid solution containing Anthocyanins extracted from grapes at various concentrations and temperatures. Results showed that the investigated chemicals, Anthocyanins extracted from grapes, performed well as tin corrosion inhibitors in 0.5M citric acid. Increasing the concentration of Anthocyanins increased their corrosion inhibition efficiencies. When the temperature dropped, their inhibition efficiencies, increased indicating that higher temperature tin dissolution predominated the adsorption of Anthocyanins at the surface of tin metal. When inhibitor concentrations were increased, their inhibition efficiencies were also increased. These results revealed that corrosion of tin metal was inhibited by a mixed type of adsorption on the metal surface. The adsorption isotherm of Langmuir governed the adsorption of Anthocyanins. Thermodynamic parameters such as the enthalpy of adsorption, the entropy of adsorption, and Gibbs free energy and kinetic parameters such as activation energy, enthalpy of activation, and entropy of activation were computed and discussed in this study.

• Corrosion Science and Technology
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• v.5 no.5
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• pp.160-167
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• 2006

S-Acetyl Isothiourea Acetate (S-AITA) was synthesized in the laboratory and this influence on the inhibition of corrosion of mild steel in 1.11 N hydrochloric and 1.12 N sulphuric acids was investigated by weight loss and potentiostatic polarization techniques at 303K, 353K and 403K. These results were confirmed by the impedance technique. The inhibition efficiency increased with increase in concentration of inhibitor and decreased with rise in temperature from 303K to 403K. The maximum inhibition efficiency of S-AITA was found to be 99.95% (0.5% of S-AITA) at 303K in sulphuric acid. The adsorption of this compound on the mild steel surface from the acids has been found to obey Temkin's adsorption isotherm. The potentiostatic polarization results revealed that S-AITA was a mixed type inhibitor. Some thermodynamic parameters i.e., activation energy (Ea), free energy of adsorption (${\Delta}G_{ads}$), enthalpy of adsorption (${\Delta}H$) and entropy of adsorption (${\Delta}S$) were also calculated from weight loss data.

• Bulletin of the Korean Chemical Society
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• v.15 no.2
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• pp.106-112
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• 1994

Six physical properties (molecular weight, heat capacity, side chain weight, side chain volume, standard entropy and partial molar volume) of amino acids, peptides and their derivatives were examined by molecular modeling techniques. The molecular connectivity index, Wiener distance index and ad hoc descriptor are employed as structural parameters to encode information about branching, size, cyclization, unsaturation, heteroatom content and polarizability. This paper examines the correlation of the molecular modeling techique's parameters and the physicochemical properties of amino acids and their derivatives. As a result, calculated values were in agreement with experimental data in the above six physical properties of amino acids, peptides and their derivatives and the molecular connectivity index was superior to the other indices in fitting the calculated data.

• Korean Journal of Community Nutrition
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• v.19 no.5
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• pp.490-498
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• 2014

Objectives: This study was conducted to propose the need of re-establishing the criteria of the body weight classification in the elderly. We compared the Asia-Pacific Region Criteria (APR-C) with Entropy Model Criteria (ENT-C) using Morbidity rate of chronic diseases which correlates significantly with Body Mass Index (BMI). Methods: Subjects were 886 elderly female participating in the 2007-2009 Korea National Health and Nutrition Examination Survey (KNHANES). We compared APR-C with those of ENT-C using Receiver Operating Characteristics (ROC) curve and logistic regression analysis. Results: In the case of the morbidity of hypertension, the results were as follows: Where it was in the T-off point of APR-C, sensitivity was 67.5%, specificity was 43.1%, and Youden's index was 10.6. While in the cut-off point of ENT-C, it was 56.7%, 56.6%, and 13.3 respectively. In the case of the morbidity of diabetes, the results were as follows: In the cut-off point of APR-C, Youden's index was 14.2. While in the cut-off point of ENT-C, it was 17.2 respectively. The Area Under the ROC Curve (AUC) of the subjects who had more than 2 diseases among hypertension, diabetes, and dyslipidemia was 0.615 (95% CI: 0.578-0.652). Compared to the normal group, the odds ratio of the hypertension group which will belong to the overweight or obesity was 1.79 (95% CI: 1.30-2.47) in the APR-C, and 2.04 (95% CI: 1.49-2.80) in the ENT-C (p < 0.001). Conclusions: We conclude that the optimal cut-off point of BMI to distinguish between normal weight and overweight was $24kg/m^2$ (ENT-C) rather than $23kg/m^2$ (APR-C).

• Journal of Korea Water Resources Association
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• v.55 no.4
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• pp.267-278
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• 2022

Recently Flood damage volume has increased as heavy rain has frequently occurred. Especially urban areas are a vulnerability to flooding damage because of densely concentrated population and property. A local government is preparing to mitigate flood damage through the heavy rain warning issued by Korea Meteorological Administration. This warning classification is identical for a national scale. However, Seoul has 25 administrative districts with different regional characteristics such as climate, topography, disaster prevention state, and flood damage severity. This study considered the regional characteristics of 25 administrative districts to analyze the flood vulnerability using entropy weight and Euclidean distance. The rainfall classification was derived based on probability rainfall and flood damage rainfall that occurred in the past. The result shows the step 2 and step 4 of rainfall classification was not significantly different from the heavy rain classification of the Korea Meteorological Administration. The flood vulnerability is high with high climate exposure and low adaptability to climate change, and the rainfall classification is low in the northern region of Seoul. It is possible to preemptively respond to floods in the northern region of Seoul based on relatively low rainfall classification. In the future, we plan to review the applicability of rainfall forecast data using the rainfall classification of results from this study. These results will contribute to research for preemptive flood response measures.

• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.685-692
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• 2016

This study aimed to develop the indicator-based approach to assess water use vulnerability in watersheds and applied to the unit watershed within the Han River watershed. Vulnerability indices were comprised of three sub-components (exposure, sensitivity, adaptive capacity) with respect to water use. The indicators were made up of 16 water use indicators. Then we estimated vulnerability indices using the Technique for Order of Preference by Similarity to Ideal Solution approach (TOPSIS). We collected environmental and socio-economic data from national statistics database, and used them for simulated results by the Soil and Water Assessment Tool (SWAT) model. For estimating the weighted values for each indicator, expert surveys for subjective weight and data-based Shannon's entropy method for objective weight were utilized. With comparing the vulnerability ranks and analyzing rank correlation between two methods, we evaluated the vulnerabilities for the Han River watershed. For water use, vulnerable watersheds showed high water use and the water leakage ratio. The indices from both weighting methods showed similar spatial distribution in general. Such results suggests that the approach to consider different weighting methods would be important for reliably assessing the water use vulnerability in watersheds.