• Journal of Institute of Control, Robotics and Systems
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• v.7 no.9
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• pp.717-722
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• 2001

This paper presents a methodology on the backward path tracking control of a trailer type robot which consists of two parts: a tractor and a trailer. It is difficult to control the motion of a trailer vehicle since its dynamics is non-holonomic. Therefore, in this paper, the modeling and parameter estimation of the system using a real-coded genetic algorithm(RCGA) is proposed and a backward path tracking control algorithm is then obtained based on the linearized model. Experimental results verify the effectiveness of the proposed method.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.579-583
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• 1999

Background: Thoracic sympathicotomy has been used safely and successfully to manage palmar hyperhidrosis. The preoperative and postoperative recording of Sympathetic Skin Responses(SSR) was performed for objective evaluation and follow-up of thoracic sympathicotomy in hyperhidrosis patients, and also for ascertaining the clinical usefullness of SSR. Material and Method: The recording of SSR was performed on 15 patients suffering from palmar hyperhidrosis with Medelec Sapphire Plus electromyogragh before and after thoracic sympathicotomy. Eletrical stimuli on the right median nerve was made in patients in supine position and results were recorded on right and left palms with soles at the same time by 4 channels. Skin temperatures were also monitored simultaneously. T2,3 sympathicotomy was performed with VATS in every patients. SSR was done in 2 patients one month later. Result: Clinically, all patients had symptomatic improvement with satisfaction. Postoperative complication was small amount of residual pneumothorax in 5 patients but it was absorbed sponteneously. There was no recurrence during follow-up period and ten patients(66%) complained compensatory hyperhidrosis. After operation, SSR change was shown in every 15 patients. Abolition of SSR on both palms was achieved in 12 patients(80%) and on both soles in 6 patients. In the other 3 patients, the latencies were significantly delayed and the amplitudes were significantly reduced at both palms and soles. In two patients who were examined at one month later after operation, similar results with postoperative SSRs were shown. The skin temperature on preoperative both palm and sole were lower than normal temperature, and those on postoperative both palm and sole were increased. Those had statistical significance(p<0.05), and the temperature on the palm was increased higher that than on the sole. Conclusion: After thoracic sympathicotomy was performed on palmar hyperhidrosis patients, an increment of skin temperatures and SSR changes were achieved at both palms and soles of all patients. Palmar SSRs were completely abolished in 12 patients(80%), and similar results of postoperative SSRs were achieved. The recording of SSR may be useful to easily and objectively assess the completeness of sympathicotomy and the follow-up of recurrence in hyperhidrosis patients.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.119-128
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• 2017

BACKGROUND: Miscellaneous cereal have been largely consumed in Korea as due to their physiological functions beneficial to human health. The cereals are currently a social concern because they have been found to contain heavy metals. Thus, monitoring heavy metals in the cereals is an important requirement for food safety analysis. In this study, we determined arsenic concentration in the cereals randomly harvested from different markets. METHODS AND RESULTS: Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection and recover test to reach $0.13-1.24{\mu}g/kg$ and 94.3-102.1%, respectively. The concentrations of inorganic arsenic equivalent to daily exposure were levels of $19.91{\mu}g/day$ in mixed grain, $1.07{\mu}g/day$ in glutinous rice, $0.77{\mu}g/day$ in black brown rice, $0.13{\mu}g/day$ in barley and $0.11{\mu}g/day$ in soybeans. CONCLUSION: The levels of arsenic in miscellaneous cereals were found lower than the recommended The Joint FAO/WHO Expert Committee on Food Additives (JECFA) levels, suggesting that the cereals marketed in Korea are not potential concern in risk assessment.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.318-327
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• 2015

BACKGROUND: Trinexapac-ethyl is a plant growth regulator (PGR) that inhibits the biosynthesis of plant growth hormone (gibberellin). It is used for the prevention of lodging, increasing yields of cereals, and reducing mowing of turf. The experiment was conducted to establish a determination method for trinexapac-ethyl and its metabolites trinexapac in agricultural products using LC-MS/MS.METHODS AND RESULTS: Trinexapac-ethyl and trinexapac were extracted from agricultural products with methanol/ distilled water and the extract was partitioned with dichloromethane and then detected by LC-MS/MS. Limit of detection(LOD) was 0.003 mg/kg and limit of quantification(LOQ) was 0.01 mg/kg, respectively. Matrix matched calibration curves were linear over the calibration ranges (0.01-1.0 mg/L) for all the analytes into blank extract withr²> 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, 50LOQ,n=5). Recoveries of trinexapacethyl and trinexapac were within the range of 73.6-106.9%, 72.7-99.2%, respectively. The relative standard deviations (RSDs) were less than 9.0%. All values were consistent with the criteria ranges requested in the CODEX guideline(CAC/GL 40, 2003).CONCLUSION: The proposed analytical method was accurate, effective and sensitive for trinexapac-ethyl and trinexapac determination and it can be used to as an official method in Korea.

• Journal of Korean Home Economics Education Association
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• v.31 no.1
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• pp.1-19
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• 2019

The purposes of this study were to concretely reveal the effect of the parents' child-rearing attitude perceived by adolescents and the school life adaptation on the problem behavior, and to verify the moderating effect of the ego-resilience on the relationship between the parents' child-rearing attitude and the school life adaptation and the adolescent problem behavior. This study analyzed a total of 2,107 students in the first year of high school, which was the 4th year data(2013) of Korea Children Youth Panel Survey(KCYPS) 2010. The reliability, descriptive statistics, t-test, and hierarchical regression analysis were conducted using SPSS WIN 22.0. The results were as follows. First, the effect of the parents' child-rearing attitude(supervision, affection, reasonable explanation, excessive interference, excessive expectation, and inconsistency), school life adaptation(relationship with teacher, relationship with friend, school regulation, and learning activity), and ego-resilience on the adolescent problem behavior was analyzed. As a result, the relationship with friend(-) had the highest influence on the adolescent problem behavior, followed by learning activity(-), inconsistency(+), ego-resilience(-), excessive interference(+), and supervision(-). However, the remaining sub-variables did not have any significant influence on the adolescent problem behavior. Second, the moderating effect of the ego-resilience on the relationship among the parents' child-rearing attitude, adaptation to school life, and adolescent problem behavior. The ego-resilience was found to moderate the effects of parents' positive child-rearing attitude, interpersonal relationships, and school adaptation on the adolescent problem behavior. However, the moderating effect was not significant for the effect of negative child-rearing attitude on the adolescent problem behavior. Therefore, various ego-resilience enhancement programs need to be developed and researched as a part of the safety education through the home economics class.

• The Journal of Engineering Geology
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• v.29 no.2
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• pp.85-97
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• 2019

It can be observed that steep slopes ($65^{\circ}$ to $80^{\circ}$) consist of rock masses were kept stable for a long time. In rock-mass slopes with similar ground condition, steeper slopes than 1 : 0.5 ($63^{\circ}$) may be applied if the discontinuities of rock-mass slope are distributed in a direction favorable to the stability of the slope. In making a decision the angle of the slope, if the preliminary rock mass conditions applicable to steep slope are quantitatively setup, they may be used as guidance in design practice. In this study, the above rock mass was defined as a good continuum rock mass and the quantitative setup criterion range was proposed using RMR, SMR and GSI classifications for the purpose of providing engineering standard for good continuum rock mass conditions. The methods of study are as follows. The stable slope at steep slopes ($65^{\circ}$ to $80^{\circ}$) for each rock type was selected as the study area, and RMR, SMR and GSI were classified to reflect the face mapping results. The results were reviewed by applying the calculated shear strength to the stable analysis of the current state of rock mass slope using the Hoek-Brown failure criterion. It is intended to verify the validity of the preliminary criterion as a rock mass condition that remains stable on a steep slope. Based on the analysis and review by the above research method, it was analyzed that a good continuum rock mass slope can be set to Basic RMR ${\geq}50$ (45 in sedimentary rock), GSI and SMR ${\geq}45$. The safety factor of the LEM is between Fs = 14.08 and 67.50 (average 32.9), and the displacement of the FEM is 0.13 to 0.64 mm (average 0.27 mm). This can be seen as a result of quantitative representation and verification of the stability of a good continuum rock mass slope that has been maintained stable for a long period of time with steep slopes ($65^{\circ}$ to $80^{\circ}$). The setup guideline for a good continuum rock mass slope will be able to establish a more detailed setup standard when the data are accumulated, and it is also a further study project. If stable even on steep slopes of 1 : 0.1 to 0.3, the upper limit of steep slopes is 1 : 0.3 with reference to the overseas design standards and report, thus giving the benefit of ensuring economic and eco-friendlyness. Also, the development of excavation technology and plantation technology and various eco-friendly slope design techniques will help overcome psychological anxiety and rapid weathering and relaxation due to steep slope construction.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.316-323
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• 2019

It is difficult to analyze pymetrozine in citrus fruits using the hydromatrix method because of its low efficiency of purification and overlap of matrix and pymetrozine peaks. Liquid-liquid extraction can analyze pymetrozine in citrus fruits using dichloromethane. Since low pH interferes with the extraction of pymetrozine, the extracts of citrus fruits were maintained over pH 7.0 by adding borax buffer and 1 N NaOH in the improved method. According to the improved method, citrus fruits (such as lemon, lime, orange, tangerine, and grapefruit) were extracted and purified for HPLC-photo diode array analysis. The results of validation were as follows: $4.360{\mu}g/kg$ of limit of detection, $14.533{\mu}g/kg$ of limit of quantitation, and 0.007 mg/kg of method quantitative limit. Citrus fruits spiked with pymetrozine showed a recovery range from 71.8 to 83.7% and a coefficient of variation below 6%. Thus, the improved method can efficiently analyze pymetrozine in citrus fruits.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.925-938
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• 2022

Agricultural reservoirs are an important water resource nationwide and vulnerable to abnormal climate effects such as drought caused by climate change. Therefore, it is required enhanced management for appropriate operation. Although water-level tracking is necessary through continuous monitoring, it is challenging to measure and observe on-site due to practical problems. This study presents an objective comparison between multiple AI models for water-body extraction using radar images that have the advantages of wide coverage, and frequent revisit time. The proposed methods in this study used Sentinel-1 Synthetic Aperture Radar (SAR) images, and unlike common methods of water extraction based on optical images, they are suitable for long-term monitoring because they are less affected by the weather conditions. We built four AI models such as Support Vector Machine (SVM), Random Forest (RF), Artificial Neural Network (ANN), and Automated Machine Learning (AutoML) using drone images, sentinel-1 SAR and DSM data. There are total of 22 reservoirs of less than 1 million tons for the study, including small and medium-sized reservoirs with an effective storage capacity of less than 300,000 tons. 45 images from 22 reservoirs were used for model training and verification, and the results show that the AutoML model was 0.01 to 0.03 better in the water Intersection over Union (IoU) than the other three models, with Accuracy=0.92 and mIoU=0.81 in a test. As the result, AutoML performed as well as the classical machine learning methods and it is expected that the applicability of the water-body extraction technique by AutoML to monitor reservoirs automatically.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.87-105
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• 2009

Nonlinear dynamic deformation characteristics, expressed in terms of normalized shear modulus reduction curve (G/$G_{max}-\log\gamma$, G/$G_{max}$ curve) and damping curve (D-$\log\gamma$), are important input parameters with shear wave velocity profile ($V_s$-profile) in the seismic analysis of (new or existing) fill dam. In this paper, the reasonable and economical methods to evaluate the nonlinear dynamic deformation characteristics for core zone and rockfill zone respectively are presented. For the core zone, 111 G/$G_{max}$ curves and 98 damping curves which meet the requirements of core material were compiled and representative curves and ranges were proposed for the three ranges of confining pressure (0~100 kPa, 100 kPa~200 kPa, more than 200 kPa). The reliability of the proposed curves for the core zone were verified by comparing with the resonant column test results of two kinds of core materials. For the rockfill zone, 135 G/$G_{max}$ curves and 65 damping curves were compiled from the test results of gravelly materials using large scale testing equipments. The representative curves and ranges for G/$G_{max}$ were proposed for the three ranges of confining pressure (0~50 kPa, 50 kPa~100 kPa, more than 100 kPa) and those for damping were proposed independently of confining pressure. The reliability of the proposed curves for the rockfill zone were verified by comparing with the large scale triaxial test results of rockfill materials in the B-dam which is being constructed.

• Journal of Korean Home Economics Education Association
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• v.30 no.2
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• pp.39-56
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• 2018

The purpose of this study was to develop Home Economics(HE) teaching and learning process plans applied Problem Based Learning(PBL) focusing on 'food and nutrition' unit for students with intellectual disability and to evaluate the effects of the HE instruction on their food choice·management knowledge and problem-solving skills after implementing the instruction for students with intellectual disability. To develop HE teaching and learning process plans applied PBL focusing on 'food and nutrition' unit for students with intellectual disability, problems that arise in daily life to trigger interest of students were firstly developed. The selected problems and teaching and learning process plans were reviewed for validity by one home economics education professor and three teachers who are experts in special education. This study used the one group pretest and posttest design, sampling 6 students who are in special-education middle school with the intellectual disability. After HE instruction of 6 sessions applied PBL method, this study tested the effects of the instruction. The first three sessions taught how to choose and keep food. The fourth session taught purchasing food ingredients and keeping them for sandwiches. The fifth and sixth sessions let the students make sandwiches and give them to others. The instruments of the study comprised of tools for food choice and management knowledge, tools for problem-solving skills evaluation, self-evaluation sheets, evaluation form of course satisfaction for students, evaluation form of behavior in class for teachers, and daily observation journal and all tools. These instruments were proved to have reliability and validity. The results of this study are as follows. First, all six students who took HE instruction applied PBL method focusing on 'food and nutrition' unit scored 30 points higher out of 100 points after taking the instruction in food choice and management knowledge and scored 5 points higher out of 14 points in problem-solving skills on average. Therefore, it was interpreted that HE instruction applied PBL affected the food choice·management knowledge and the problem solving skills of students with intellectual disability. Secondly, the students with intellectual disability participated actively in HE instruction applied PBL focusing on 'food and nutrition' unit and expressed satisfaction. Three special education experts evaluated HE teaching·learning process plans applied PBL focusing on 'food and nutrition' unit to be well-developed. This study showed that HE instruction applied PBL focusing on 'food and nutrition' unit allowed the students with intellectual disability to acquire comprehensive skills in choosing, keeping, and making safe food and helped them solve problems of their life by themselves. Therefore I suggest that Home Economics should be adopted as a formal subject matter in special school curriculum for students with intellectual disability.