• Magazine of the Korean Society of Agricultural Engineers
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• v.21 no.3
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• pp.83-91
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• 1979

This study was conducted in order to find out the performance of rice transplanters in accordance with the change of the trans-planting days after pudding and the water depth flooding the paddy field at the time of transplanting : and thus to select the optimum paddy field preparation procedures for an efficient utilization of rice transplanters. The performance factors of the two different types of rice transplanters were measured during the first 6 consecutive days after puddling and with 3 different levels of water depth flooding the paddy fields. The results of this study were analysed and summarized as follows : 1. Wheel sinkage decreased very rapidly from 0 to 2 days after puddling and slowly from 3 to 5 days after puddling. 2. The depth of the test cone penetration decreased rapidly during the first few days after puddling. It was 17.8cm just after puddling, and decreased to 13.4cm one day after puddling. After 2 days, the rate of decrease was dampened, and after 5 days it kept constant value of 9.2cm. 3. Two days after puddling, the hill interval was 15.8cm (98.75% of the preset value) for broadcasted seedling rice transplanter with 3cm flooding depth : This value was the closest to the pre-adjusted value of 16cm. The general performance of broadcasted-seedling type rice transplanter was better than that of strip-seedling type rice transplanter. 4. Usually the working performance of a rice transplanter is evaluated with uniformity and adjustability of the hill intervals. The hill interval was the most uniform and closest to the pre-set value of 16cm when planted two days after puddling with 3cm of water depth. When it was inavoidable to plant 4 days after puddling with stripseedling type rice transplanter, it is advisable to let the water flooded somewhat deeper. 5. The percentage of missing hills including floating and burried seedlings was the highest just after puddling and ie decreased substancially until 3 days after puddling and then it increased again. Hence, the optimal time transplanting is to be between 2 and 3 days after puddling. 6. Better postures of planted seedlings were found when planter 2 days after puddling than 3 days after puddling. Six cm of flooding water depth always gave the best results with respect to the postures of planted seedlings. Broadcasted-seedling rice transplanter, in general, showed better posture of planted seedlings than did strip-seedling type rice transplanter. 7. Judging from the above results, the optimal conditions will be 3cm of flooding depth and transplanting between 2 and 3 days after puddling.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.3
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• pp.192-200
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• 2022

The association between heavy metals in the blood and obesity has been examined in many studies. However, inconsistencies have been observed in the results from these studies. The present study was conducted using data from 119,181 participants of the Korea National Health and Nutrition Examination Survey (KNHANES) for 11 years in 2005 and between 2008 and 2017. The subjects with missing heavy metal blood tests, health interview data, and health examination data were excluded from the study. The study population comprised 1,844 individuals (972 men, 872 women) who were eligible for inclusion. It was found that obesity and abdominal obesity were associated with an increase in both blood mercury (P<0.001) and alanine aminotransferase (ALT) (P<0.001). After adjusting the confounding factors, those with concurrent high levels of ALT and the highest tertile of mercury showed an increased risk of obesity (odds ratio 4.46, 95%, confidence interval 2.23~8.90, P<0.001) as well as abdominal obesity (odds ratio 5.36, 95%, confidence interval 2.57~11.17, P<0.001). The interrelationship of mercury and ALT with the parameters of body mass index (P for interaction=0.009) and waist circumference (P for interaction=0.012), respectively, have been observed to be significant, suggesting that the reciprocal relationship could contribute to obesity and abdominal obesity.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.205-210
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• 2020

Children should be provided with the right to be protected by adults, related organizations, or countries because they lack power, situation recognition ability, and situation judgment ability compared to adults. Also, children's accidents and accidents caused by neglect of management occur every year. Currently, there are about 3 to 20 children managed by one teacher in a daycare center, and it is very difficult for teachers to care for all children as many children have to be managed. Especially, when outdoor activities are conducted in open space, children's activities are expanded compared to the in-house, and children who do not follow the control of the in-house teacher may occur, so there is a limit to the control and management of children depending on the viewpoint of teachers. In this study, we designed and implemented IoT terminal and system to provide safety to children and to provide convenience to guardians and teachers by systemizing the location or interval between children and in-service teachers using portable devices that can communicate with each other. It is hoped that this will contribute to the safety of infants.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.343-353
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• 2013

Flow duration curve (FDC) can be developed by linking the daily flow data of stream flow monitoring network to 8-day interval flow data of the unit watersheds for the management of Total Maximum Daily Loads. This study investigated the applicable method for the development of long term FDC with the selection of the stream flow reference sites, and suggested the development of the FDC in 4 river basins. Out of 142 unit watersheds in 4 river basins, 107 unit watersheds were shown to estimate daily flow data for the unit watersheds from 2006 to 2010. Short term FDC could be developed in 64 unit watersheds (45%) and long term FDC in 43 unit watersheds (30%), while other 35 unit watersheds (25%) were revealed to have difficulties in the development of FDC itself. Limits in the development of the long term FDC includes no stream monitoring sites in certain unit watersheds, short duration of stream flow data set and missing data by abnormal water level measurements on the stream flow monitoring sites. To improve these limits, it is necessary to install new monitoring sites in the required areas, to keep up continuous monitoring and make normal water level observations on the stream flow monitoring sites, and to build up a special management system to enhance data reliability. The development of long term FDC for the unit watersheds can be established appropriately with the normal and durable measurement on the selected reference sites in the stream flow monitoring network.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1257-1264
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• 2019

The traditional cuff-based method for BP(Blood Pressure) measurement is not suitable for continuous real-time BP measurement techniques. For this reason, the previous studies estimated various blood pressures by fusion with the electrocardiography (ECG) and photoplethysmogram (PPG) sensor signals. However, conventional techniques based on PPG bio-sensing measurement face many challenging issues such as noisy supply fluctuation, small pulsation, and drifting non-pulsatile. This paper proposed a novel BP estimation methods using PPG and ECG sensors, which can be derived from the relationship between PPG and ECG using PTT(Pulse Transit Time) and PWV(Pulse Wave Velocity). Unlike conventional height ratio features, which are extracted on the basis of the peaks in the PPG and ECG waveform. The proposed method can be reliably obtained even if there are missing peaks among the sensed PPG signal. The increased reliability comes from periodical estimation of the peak-to-peak interval time using ECG and PPG. After 250,000 times trials of the blood pressure measurement, the proposed estimation technique was verified with the accuracy of ±28.5% error, compared to a commercialized BP device.

• Journal of Preventive Medicine and Public Health
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• v.50 no.5
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• pp.303-310
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• 2017

Objectives: The aim of this study was to evaluate socioeconomic inequalities in the prevalence of dental caries among an urban population. Methods: This study was conducted among 2000 people 15-40 years of age living in Kurdistan, Iran in 2015. Using a questionnaire, data were collected by 4 trained dental students. The dependent variable was the decayed, missing, and filled teeth (DMF) index. Using principal component analysis, the socioeconomic status (SES) of families was determined based on their household assets. Inequality was measured using the concentration index; in addition, the Oaxaca analytical method was used to determine the contribution of various determinants to the observed inequality. Results: The concentration index for poor scores on the DMF index was -0.32 (95% confidence interval [CI], -0.40 to -0.36); thus, poor DMF indices had a greater concentration in groups with a low SES (p<0.001). Decomposition analysis showed that the mean prevalence of a poor DMF index was 43.7% (95% CI, 40.4 to 46.9%) in the least privileged group and 14.4% (95% CI, 9.5 to 9.2%) in the most privileged group. It was found that 85.8% of the gap observed between these groups was due to differences in sex, parents' education, and the district of residence. A poor DMF index was less prevalent among people with higher SES than among those with lower SES (odds ratio, 0.31; 95% CI, 0.19 to 0.52). Conclusions: An alarming degree of SES inequality in oral health status was found in the studied community. Hence, it is suggested that inequalities in oral health status be reduced via adopting appropriate policies such as the delivery of oral health services to poorer groups and covering such services in insurance programs.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.119-129
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• 2014

PURPOSES : This investigational survey is to observe a proper spatial aggregation method for path travel time estimation using the hi-pass DSRC system. METHODS : The links which connect the nodes of section detectors location are used for path travel time estimation traditionally. It makes some problem such as increasing accumulation errors and processing times. In this background, the new links composition methods for spatial aggregation are considered by using some types of nodes as IC, JC, RSE combination. Path travel times estimated by new aggregation methods are compared with PBM travel times by MAE, MAPE and statistical hypothesis tests. RESULTS : The results of minimum sample size and missing rate for 5 minutes aggregation interval are satisfied except for JC link path travel time in Seoul TG~Kuemho JC. Thus, it was additionally observed for minimum sample size satisfaction. In 15, 30 minutes and 1 hour aggregation intervals, all conditions are satisfied by the minimum sample size criteria. For accuracy test and statistical hypothesis test, it has been proved that RSE, Conzone, IC, JC links have equivalent errors and statistical characteristics. CONCLUSIONS : There are some errors between the PBM and the LBM methods that come from dropping vehicles by rest areas. Consequently, this survey result means each of links compositions are available for the estimation of path travel time when PBM vehicles are missed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.144-151
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• 2020

Agrivoltaic systems (AVS) is defined as combining farm-grown crops with photovoltaic panels (PV) installed several meters above the ground. Solar radiation (W/㎡), photosynthetic photon flux density (PPFD, µmol/㎡/s), air temperature (℃), vapor pressure (kPa), soil moisture (㎥/㎥), soil temperature (℃), wind direction (˚), and wind speed (m/s) were measured under the AVS in Boseong-gun during winter barley season. Data was collected by 5 minute interval. All data can download at Github site (https://github.com/chojaeil/AVS_Boseung). To gap-filling missing solar radiation data during about two weeks, the conversion coefficient from solar radiation to PPFD was estimated as 0.41. Further, according to the ratio of diffuse radiation to direct radiation, the maximum value among the twenty PPFD sensors under the AVS was related to the PPFD value of filed.

• Imaging Science in Dentistry
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• v.35 no.2
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• pp.97-103
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• 2005

Purpose : To determine if ultrasonography is a reliable technique to assess masseter muscle sites within intra- and interobserver and the scanning level and/or the muscle condition affect local cross-sectional dismension (LCSD) measurements of masseter muscle. Materials and Methods : 10 subjects without sign and symptom of temporomandibular disorders and missing posterior teeth were examined by ultrasonography. Bilateral ultrasonographic examinations were performed with a linear (B-scan) 7.5 MHz small-part transducer to register LCSDS of the masseter muscle on three different levels. Scans were made on relaxed and clenching condition. Three oral and maxillofacial radiologists measured at two sessions with a time interval of at least 5 minutes. Results : Variables such as 'condition' and 'level' had a significant effect on muscle measurements (p<0.05). There was no significant difference between 'sessions'(p>0.05) and 'observers' (p>0.05). LCSDS on lower scan level were significantly thinner than those on upper and middle level. Those on clenching condition were significantly thicker than those on relaxed condition (p<0.05). The scanning level with the highest reproducibility was middle with clenching condition (ICC=0.90, $MSE=0.55\%$). Conclusion : The data suggested that ultrasonography was a reliable method for measuring LSCD of masseter muscle in intra- and Interobserver and middle scan level showed the most reliable data.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.3
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• pp.231-238
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• 1995

The scapular flap, described by dos Santos in 1986, has been used successfully for the reconstruction of a variety of defects of oro-mandible. Some have defined the gross and vascular anatomy of the lateral border of the scapula, yet useful anatomical information and a complete description of area and contour of each cut surface of lateral border of scapula, which is very important for esthetic and functional reconstruction using dental implants, are missing. These prompted us to clarify the cross-sectional area of lateral border of scapula. Twenty three scapulas of 15 fixed adult Caucasian cadavers were sectioned in every 1cm interval along the lateral border of scapular, and the metric relations and the shape of cut surface were assessed. The lateral border of the scapula, consisting of cortico-cancellous bone measuring $7.86{\pm}0.97mm$ in width, $19.6{\pm}2.86mm$ in height and $12{\pm}1.78cm$ in length, could be harvested as an osteocutaneous scapular flap or as a single vascularized bone flap. The mean thickness of cortical bone of lateral, medial, dorsal and costal surface was $0.46{\pm}1.48mm$, $1.78{\pm}1.34mm$, $1.54{\pm}1.11mm\;and\;1.35{\pm}0.87mm$, respectively. So we have thought that all scapular transplants could be supported osseointegrated implants for fixation of dental prosthesis.