• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.44.4-45
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• 2018

(4179) Toutatis (Toutatis hereafter) is one of the Near-Earth Asteroids which has been studied most rigorously not only via ground-based photometric, spectroscopic, polarimetric, and radar observations, but also via the in-situ observation by the Chinese Chang'e-2 spacecraft. However, one of the most fundamental physical properties, the geometric albedo, is less determined. In order to derive the reliable geometric albedo and further study the physical condition on the surface, we made photometric observations of Toutatis near the opposition (i.e., the opposite direction from the Sun). We thus observed it for four days on 2018 April 7-13 using three 1.6-m telescopes, which consist of the Korean Microlensing Telescope Network (KMTNet). Since the asteroid has a long rotational period (5.38 and 7.40 days from Chang'e-2, Zhao et al., 2015), the continuous observations with KMTNet matches the purpose of our photometric study of the asteroid. The observed data cover the phase angle (Sun-asteroid-observer's angle) of 0.65-2.79 degree. As a result, we found that the observed data exhibited the magnitude changes with an amplitude of ~0.8 mag. We calculated the time-variable geometrical cross-section using the radar shape model (Hudson & Ostro 1995), and corrected the effect from the observed data to derive the geometric albedo. In this presentation, we will present our photometric results. In addition, we will discuss about the regolith particles size together with the polarimetric properties based on the laboratory measurements of albedo-polarization maximum.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.2
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• pp.13-30
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• 2019

The purpose of this study was to investigate changes in vegetation and flora after five years through field surveys data with the Han Gang Watershed Management Committee (2013) data in order to observe natural vegetation changes in the riparian zone of Han River watershed. As a result, the flora of the riparian zone in 2012 were listed total 231 taxa, 66 families, 158 genus, 207 species, 23 varieties, and 1 forms, and in 2017, a total 247 taxa, 74 families, 174 genus, 218 species, 27 varieties, and 2 forms were identified. The number of rare plants decreased from 4 taxa in 2012 to 2 taxa in total in 2017, and the number of endemic plants increased from 1 taxa to 3 taxa. The number of specific plants by floral region decreased from 21 taxa (9.1% of all 231 taxa of flora) in 2012 to 16 taxa (6.5% of all 247 taxa of flora) in 2017. The total number of naturalized plants is analyzed to increase from 35 taxa, a naturalization rate of 15.15% (all 231 taxa of flora) and urbanization index of 11.2% (all 312 taxa of naturalized plants) in 2012 to 44 taxa a naturalization rate of 17.8% (all 231 taxa of flora) and urbanization index of 14.1%(all 312 taxa of naturalized plants) in 2017. The ecosystem disturbance species showed an increase in both number of species and cover degree grades, indicating that the riparian zone changed in a negative direction.

• Fashion & Textile Research Journal
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• v.25 no.2
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• pp.185-198
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• 2023

The purpose of this study is to obtain information necessary for the development of patient clothes that can reduce physical fatigue of caregivers by quantitatively measuring the muscle load and fatigue. The patient clothes used in this study can be broken down into three types: A type (back center zipper open suit), B type (top-to bottom separated patient clothes), and C type (front zipper open suit). The EMG measurement sites are as follows: hand muscle (brachioradialis), upper arm (biceps, triceps), shoulder (anterior deltoid, medial deltoid, posterior deltoid, upper trapezius), and waist (erector spinae); additionally, the EMG signals were measured. Through this experiment, muscle load, muscle energy consumption, and muscle fatigue generation tendency were analyzed. The results of the study revealed that the C type patient clothes required the most strength in the muscles of the shoulders, upper arms, hands, and back when being put on and taken off compared to other patient clothes. The A type clothes required a relatively large force in opening the zipper. In terms of muscle energy consumption, B type generally called for more strength when it came to the zip-up and putarmsup motions. With regard to the cover the body and put legs/hips up motions, C type used the highest amount of muscle energy, whereas A type used relatively little energy. In terms of the occurrence of muscle fatigue during the putting on and taking off of the patient's clothing, there was a difference in the area and degree of muscle fatigue in the A, B, and C types, and there was also a tendency for muscle fatigue to occur when performing repetitive movements.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.638-651
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• 2023

The objective of this study was to quantitatively estimate the level of grazing area damage in outdoor free-range pig production using a Unmanned Aerial Vehicles (UAV) with an RGB image sensor. Ten corn field images were captured by a UAV over approximately two weeks, during which gestating sows were allowed to graze freely on the corn field measuring 100 × 50 m². The images were corrected to a bird's-eye view, and then divided into 32 segments and sequentially inputted into the YOLOv4 detector to detect the corn images according to their condition. The 43 raw training images selected randomly out of 320 segmented images were flipped to create 86 images, and then these images were further augmented by rotating them in 5-degree increments to create a total of 6,192 images. The increased 6,192 images are further augmented by applying three random color transformations to each image, resulting in 24,768 datasets. The occupancy rate of corn in the field was estimated efficiently using You Only Look Once (YOLO). As of the first day of observation (day 2), it was evident that almost all the corn had disappeared by the ninth day. When grazing 20 sows in a 50 × 100 m² cornfield (250 m²/sow), it appears that the animals should be rotated to other grazing areas to protect the cover crop after at least five days. In agricultural technology, most of the research using machine and deep learning is related to the detection of fruits and pests, and research on other application fields is needed. In addition, large-scale image data collected by experts in the field are required as training data to apply deep learning. If the data required for deep learning is insufficient, a large number of data augmentation is required.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.30.1-30.1
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• 2020

The ASKAP-EMU survey is a deep wide-field radio continuum survey designed to cover the entire southern sky and a significant fraction of the northern sky up to +30°. Here, we report a discovery of a radio relic in the merging cluster SPT-CL J2023-5535 at z=0.23 from the ASKAP-EMU pilot 300 square degree survey (800-1088 MHz). The deep high-resolution data reveal a ~2 Mpc-scale radio halo elongated in the east-west direction, coincident with the intracluster gas. The radio relic is located at the western edge of this radio halo stretched ~0.5 Mpc in the north-south orientation. The integrated spectral index of the radio relic within the narrow bandwidth is α1088MHz800MHz = -0.76 ± 0.06. Our weak-lensing analysis shows that the system is massive (M200 = 1.04 ± 0.36 × 1015M⊙) and composed of at least three subclusters. We suggest a scenario, wherein the radio features arise from the collision between the eastern and middle subclusters. Furthermore, the direct link between the local AGN and the relic along with the discontinuities in X-ray observation hint us that we are looking at the site of re-acceleration.

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.10-17
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• 2024

In Korea, the common remedial process for reclamation of agricultural soils nearby abandoned mines involves chemical soil stabilization followed by covering with clean soil. This study investigated the chemical properties of cover soils and the validity of HCl extraction method in assessing the degree of As and heavy metal stabilization in stabilized soils collected from 14 plots where mine reclamation had been completed. The results revealed there were no major differences in contaminants extraction rate between the stabilized soils and contaminated soils, suggesting HCl extraction procedure is a less feasible method to determine the efficiency of the stabilization. Soil quality indicators including OM, SiO₂, P₂O₅, etc. of the land-covering soils were generally lower than those of stabilized soils that used to be the cultivation layer before the stabilization. Nonetheless, the value of those indicators didn't meet the regulatry limits of agricultural soil. Therefore, future strategy for mine reclamation should concentrate not only on contaminant concentration but also on soil quality parameters for agricultural use of the reclaimed soil.

• Korean Journal of Remote Sensing
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• v.28 no.5
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• pp.587-596
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• 2012

Verifying about eligibility of targeted site is necessary for execute Afforestation and Reforestation Clean Development Mechanism (A/R CDM) project which is followed by system of Kyoto protocol. The site have to be identified by which could not be in conformity with definition of forest. This study tried to propose a technology of classify for site selection of A/R CDM. We chose several parts of Yangpyeng as study area and applied LiDAR data and remotely sensed imagery for considering about tree height, degree of crown closure, and land area which 3 factors for identify forest. LiDAR data was used for offset the shortage of remotely sensed imagery that cannot perfectly determine the forest definition due to absence of 3-dimentional information, but can be obtained from LiDAR. Considering tree height, degree of crown closure, and land area simultaneously by moving window, classified fields to forest and non forest based on pixel size. As a result, 124.06 ha for suitable to doing plantation and approximately 357.02 ha are in negative. Technology that applied for analyzing will provide fundamental methodology not only site selection for A/R CDM, but will be utilized in other Kyoto protocol.

• Research in Community and Public Health Nursing
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• v.10 no.1
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• pp.227-238
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• 1999

The goal of this study is to discover the effect of sex education on sex-related knowledge and attitudes of middle school girls. Non-equivalent control group pretest-posttest design was used. The number of experimental group students was 134 and the number of control group students was 134. A total of 268 second grade middle school girls were selected for a convenience sampling method. This study was carried out in a middle school located in Taegu City, Korea, from February 5 to February 18, 1998. To des cover the needs of sex education, the researcher sent a predesigned questionnaire to 1464 girls in 19 different middle schools. The sex education curriculum was designed on the basis of this survey's results. 'The Sex Education Teaching Plan' (published by the Research Institution of Korean School Health Education) and 'Sex and Happiness' (published by the Seoul City Education Ministry) were used to redesign the sex education curriculum and content. Fifty minute long sex education classes were taught to the experimental group every other day and the total number of classes was five. The contents of the teaching -learning plan for sex education were: 'The Characteristics of Adolescence', 'Pregnancy and Contraception', 'Friendship with the Opposite Sex and Prevention of Sexual Violence', 'Prevention of Venereal Disease', and 'Sex and Society'. To measure the degree of sex knowledge of the subjects, the researcher used the modified sex knowledge tools of Kim(l995) and Han(1997). The reliability values of these sex knowledge tools range from 0.71 to 0.74, using Cronbach's alpha. To measure the degree of sex attitude in the subjects, the researcher used the modified sex attitudes tools of Han(l997). The reliability values of these sex attitude tools range from 0.73 to 0.78 using Cronbach's alpha. The PC-SAS package program was used to analyse the data along with Frequency, Percentage, XLtest, t -test, and a paired t -test The results of this study were as follows; 1. The first hypothesis was accepted. The experimental group showed more change in sex - related knowledge than the control group(t =22. 76, p=0.0001). 2. The second hypothesis was accepted. The experimental group showed more change in sex-related attitudes than the control group (t=11.91, p=0.0001). In conclusion, the level of sex-related knowledge and sex-related attitudes of middle school girls who received sex education was higher than that of the girls who did not receive sex education. According to this research, planned sex education was effective in forming accurate knowlege and appropriate attitudes related to sex. Clearly, we must carry out a well-designed step by step sex education program that is well-suited to the sex education needs and the developmental level of the students.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.254-260
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• 1999

Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS data transmission is needed; often ranges more than 1000 km. It has been, however, so far considered unsuitable for short distance application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper extensively analyzes characteristics of shot distance MB(Meteor Burst) path and shows the low duty rate may be improved by increasing burst rate through adapting antenna beam width to cover entire hot-spot region in the space and, by compensating effective burst length through cutting down man-made noises introduced by antenna. Based on the analysis, we are developed a small-opening-cavity antenna, especially designed for short distance MB path. In operation, the antenna is to be buried under ground surface so as to improve directivity and reduces noise introduction. The antenna exhibits power gain of 3 dB with 90 degree beam width and thus enables to illuminate entire hot-spot regions with the elevation angle of 8-90 degree which is the case of transmission less than 100 km. Directivity horizontal to earth surface is suppressed to minimum which enables to cut man-made noises from near-by sources down to more than 3 dB from the level reported with conventional 4 element Yagi. A series of experiments performed on 100 km MB paths have conformed that, with the antenna installed at receiving site, the burst rate and duration time have been noticed to increase by 10 and 20 percent respectively from the values obtained by conventional 4-element Yagi antenna under same testing condition.

• Journal of the Korean Dietetic Association
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• v.6 no.2
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• pp.136-147
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• 2000

The aim of this research was to examine the management practices related to foodservice.clinical nutrition service provided by hospital foodservice operations. A survey of 30 hospital food nutrition service departments was undertaken and detailed information was collected from each, including surveys of 176 dietitians and 30 foodservice managers. Statistical data analysis was completed using the SAS/win 6.11 package for descriptive analysis and t-test. The results of this study can be summarized as follows : Out of 30 hospitals, 73.3%(22) were directly operated and 26.7%(8) were under contract foodservice management. Licensed number of beds were 768.7, with an average length of 11.4 days. The general characteristics of the dietitians were that 49.4% were aged between 25-29, and 60.8% were ordinary dietitians. 76.7% had bachelor's degree, 15.9% with master's degree and 7.4% were college graduates. Most hospital dietitians had internship training and 35.2% took a training course of 6 to 12 months. The average space of kitchen was 452.52 $m^2$, with 133.63$m^2$ for modified diet space and 18.13$m^2$ for nutrition counselling room space. The total number of normal meals was 1,255.47, with 502.93 of modified meals. The average calorie of normal meals was 2,145.04kcal, with 91.9g of protein contained in normal meal. The total food waste was 351.40kg. An average monthly cost for disposing food waste was 745,171.67 won. 83.3% of the kitchens were on the 1st basement and only 66.7%(20) of 30 hospitals had its own nutrition counselling room. 80% used dishwashers and 66.7% had an exclusive elevator for delivering meals. 80.0% of hospitals used centralized delivery service. 90% had established an area for hygiene division, 70% used dry zone within the dishwashers for sterilization, 66.7% provided spoon and chopstick, and 100% used dish cover. As means of food waste treatment, most hospitals(56.7%) used animal feed by contracters, followed by means of collection by contracters(30%) and in-house high speed fermentation machines(13.3%). It was found that only 33.3% hospitals regularly checked temperatures of the meals given to patients. Total productivity index was 3.72(meals/hour) in average, with an average productivity index for normal diet of 5.41. Average productivity index for modified diet was 4.62. Productivity indices for patient meals and clinical nutrition were 5.01(meals/hour) and 1.12(cases/hour) respectively and hospitals under self-operated foodservice management received higher points on clinical nutrition productivity index(P<0.01) than hospitals under contract foodservice management.