• Journal of the Korean Society of School Health
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• v.17 no.1
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• pp.85-95
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• 2004

Objectives : The aim of this study was to identify the trend of school health research by analyzing articles related to school health for the last 10 years. this information can be used to guide research direction for the future. Methods : This study is a descriptive study that analyzed annual data. using an objective frame of evaluation about the methodology and research domain in each paper, all the papers included in the journals concerning school health from January 1993 to December 2000 were analyzed. The data was processed statistically by frequency and percentage. Results : 455 papers in 9 journals related to school health were published. The Journal of the Korean Society of School Health had 204 articles, the highest number of any journal. most of the articles were descriptive, but the number of experimental studies increased over time. the most common research subjects were students were the greatest ones, but the trend to study both parents and teachers increased near the end of the sampling period. the most common selection of subjects appeared to be based on convenience, but probability sampling gradually increasing annually. the most common research instrument was the questionnaire and the reliability and the validity of instruments were described in approximately half of the studies. The survey was the most commonly used method of data collection. The papers that met ethical issue in data collection were less than those that did not. In addition, the papers that provided the rationale for the calculation of sample size were less than those that did not. parametric statistics were the main methods of data analysis, but some advanced statistics were used more often than simple descriptive statistics in the latter part of the sampling period. In general, limit of the studies were not frequently mentioned but more recommendations were made. regarding the characteristics of the research area, the assesment domain was remarkable. The rate of school health problem assesment was the highest among research subjects. Sex- related subjects were the highest in detail research subjects. Conclusions : The research of school health has increased quantitatively, but it is difficult to ascertain its qualitative development. Therefore, on the basis of the research completed up until now, more school-based intervention studies and longitudinal studies need to be another target for the evaluation of the effects of the school health service. as well, policy suggestion through international and cross-sectional comparison studies are needed to assist in the establishment of the long term direction of school health.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.5
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• pp.62-70
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• 2007

In this paper, the boost Power Factor Correction(PFC) technique for Direct Torque Control(DTC) of brushless DC motor drive in the constant torque region is implemented on a TMS320F2812DSP. Unlike conventional six-step PWM current control, by properly selecting the inverter voltage space vectors of the two-phase conduction mode from a simple look-up table at a predefined sampling time, the desired quasi-square wave current is obtained, therefore a much faster torque response is achieved compared to conventional current control. Furthermore, to eliminate the low-frequency torque oscillations caused by the non-ideal trapezoidal shape of the actual back-EMF waveform of the BLDC motor, a pre-stored back-EMF versus position look-up table is designed. The duty cycle of the boost converter is determined by a control algorithm based on the input voltage, output voltage which is the dc-link of the BLDC motor drive, and inductor current using average current control method with input voltage feed-forward compensation during each sampling period of the drive system. With the emergence of high-speed digital signal processors(DSPs), both PFC and simple DTC algorithms can be executed during a single sampling period of the BLDC motor drive. In the proposed method, since no PWM algorithm is required for DTC or BLDC motor drive, only one PWM output for the boost converter with 80 kHz switching frequency is used in a TMS320F2812 DSP. The validity and effectiveness of the proposed DTC of BLDC motor drive scheme with PFC are verified through the experimental results. The test results verify that the proposed PFC for DTC of BLDC motor drive improves power factor considerably from 0.77 to as close as 0.9997 with and without load conditions.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.360-372
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• 2010

Concentrations of ambient air particles such as total suspended particulates (TSP), particulate matter $(PM)_{10}$, and $PM_{2.5}$, were monitored simultaneously from May to June, 2007, at four locations at Alashan and Beijing in China, and Seoul and Gosan in South Korea. These monitoring sites are in the pathway of Asian dust (AD) storms traveling from China to the Korean peninsula. An AD event was observed in the Korean peninsula on May 25-26. During the sampling period, the average concentrations of TSP and PM10 were each higher than $150\;{\mu}g/m^3$ in Alashan and Beijing, but not in Seoul and Gosan. The concentration of TSP in Alashan (where the dust storm originated) on the day of the AD event reached $1824.7\;{\mu}g/m^3$, this being the highest concentration of air particles observed during the sampling period. The level was decreased to 15% of this ($274.7\;{\mu}g/m^3$) in Seoul and to 8.7% ($159.0\;{\mu}g/m^3$) in Gosan when the AD was observed two days later in Korea. Gosan, a representative background site in East Asia, displayed the lowest concentration of particles, with this maximal TSP concentration of $159\;{\mu}g/m^3$. Inorganic element contents in the air particles were also measured, and the concentrations in the four different regions compared. Concentrations of anthropogenically-enriched heavy metals in $PM_{10}$ and $PM_{2.5}$, such as lead, arsenic, cadmium, and mercury, were higher in the metropolitan cities of Beijing and Seoul compared to non-industrialized regions of Alashan and Gosan. However, the concentrations of inorganic soil elements including iron, magnesium, aluminum sodium, and manganese, were higher in Alashan compared to those in other sampling sites.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.162-175
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• 2008

Gyeongju, which was the central city of the ancient civilization at Silla Kingdom, has various kinds of stone cultural properties. It is significantly important to preserve historical sources of Korea. However, recent air quality data measured in Gyeongju did not show good air quality level. In order to investigate variation of the concentration of the air pollutants with meteorological condition, an air quality monitoring and an aerosol sampling were conducted during the intensive monitoring period in Gyeongju. Impacts of the meteorological factors on the air pollutants were also analyzed based on the air mass pathway categories using HYSPLIT model and the local wind patterns using MM5 model. The prevailing air mass pathways were classified into four categories as following; category I affected by easterly marine aerosols, category II affected by northwesterly continental aerosols, category III affected by southwesterly continental aerosols, and category IV affected by northerly continental aerosols. The concentrations of the air quality standards were relatively lower during the fall intensive monitoring period. At that time, the easterly marine air mass pattern was dominated. The seasonal average mass concentration of $PM_{10,Opt}$, which optically measured at the monitoring site, was the highest value of $77.6{\pm}28.3\;{\mu}g\;m^{-3}$ during the spring intensive monitoring period but the lowest value of $20.1{\pm}5.3\;{\mu}g\;m^{-3}$ during the fall intensive monitoring period. The concentrations of $SO_2$ and CO were relatively higher when the air mass came from the northwestern continent or the northern continent. The concentrations of ${SO_4}^{2-}$ and ${NO_3}^-$ increased under the northwesterly continental condition. It was estimated that the acidic aerosols were dominated in the atmosphere of Gyeongju when the air mass came from the continental regions.

• Journal of International Academy of Physical Therapy Research
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• v.7 no.2
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• pp.1056-1065
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• 2016

The purpose of this study was to determine the effects of music therapy and ball exercise on women experiencing menstrual discomforts, thereby identifying the validity of these methods as interventions against menstrual discomforts, with a particular goal of presenting basic data for clinical use. Twenty university students in their 20s were assigned to two therapy groups in a sequence via simple random sampling; ten subjects attended a ball exercise combined with music therapy group and the other ten subjects attended a music therapy group. Ball exercises were conducted 3 times per week for a total of 12 times, starting from 3 weeks before the expected first day of the menstrual period and ending on the last day of the menstrual period. Similarly, the subjects participated in music therapy by listening to music for 35 minutes per session and 3 sessions per week, starting from 3 weeks before the expected first day of the menstrual period and ending on the last day of the menstrual period. Five out of six categories of menstrual discomforts were significantly decreased in both music therapy and ball exercise, the exception being changes in the autonomic nervous system, while those in the music therapy group showed a significant difference only in the category of behavioral changes. The results of the present study demonstrate that the ball exercise combined with music therapy more effective in improving menstrual discomforts than the music therapy group.

• International Journal of Knowledge Content Development & Technology
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• v.12 no.1
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• pp.17-34
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• 2022

This informetrics study was conducted to find out the distribution of articles and authors that published in African Journal of Library, Archives and Information Studies [AJLAIS]) from 2009 to 2018; considering the year-wise growth of research articles; authorship pattern and collaboration ratio; subject and geographical distributions of authors; and authors' productivity level. A descriptive informetrics research design was adopted. Quota sampling technique was used to select all the articles published within the ten-year period. Data collected through a self-designed checklist was analyzed using frequency count and percentage. The findings revealed that 141 articles, contributed by 266 authors were published by AJLAIS during the period. An annual average growth of 1.20% was recorded. Overall year-wise authorship pattern revealed that majority of articles (62.41%) published in AJLAIS were multiple authored. Also, articles on Informetrics and ICT dominated the journal. Some subject areas not covered were identified such as: indexing and serial collections management. Average collaborative index across the 10-year period for the journal was 0.62. South Africa and Nigeria were the two major prolific contributors to AJLAIS, just as evidence-based research papers of survey type (65.25%) were the most common to the journal. There should be increased numbers of articles in each edition over the coming years, and awareness should be created by the publishers to familiarize the researchers with the publishing requirements of the journal. Also, LIS researchers should concentrate more on areas usually left untouched by previous studies. The study is original as no other similar study was found on publication pattern of articles in AJLAIS covering a ten year period of 2009-2018. The findings of the study will also serve as a feedback mechanism for the Publisher of the Journal and LIS researchers on how to improve the journal and LIS research in general.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.4
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• pp.315-326
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• 2013

This study investigated the temporal-spatial distribution and variations in water quality parameters (temperature, salinity, pH, DO, COD, SPM, DIN, DIP, silicate, TN, TP, and chlorophyll-a) in the coastal area of Jeju, Korea, adjacent to aquaculture ponds (Aewol-ri, Haengwon-ri, Pyosun-ri, and Ilkwa-ri). Data were collected bimonthly from February 2010 to December 2011. A principal component analysis (PCA) identified three major factors controlling variations in water quality during the sampling period. Aquaculture effluent water led to large changes in nutrient levels. The highest nutrient values were observed during the investigation period. The relatively large increase in organic matter at the sampling stations coupled with sea area runoff events during the summer rainy period. Variation in chlorophyll-a concentration was mainly driven by meteorological factors such as air temperature and rainfall in the coastal areas of Aewol and Haengwon. In the coastal areas of Pyosun and Ilkwa, pollution was caused by anthropogenic factors such as discharge of aquaculture effluent water. High nutrient concentrations at the majority of the coastal stations indicate eutrophication of coastal waters, especially within a distance of 300 m and depth of 10m from drainage channels. Coastal eutrophication driven by aquaculture effluent may be harmful inshore. Events such as eutrophication may potentially influence water pollution in aquaculture ponds when seawater intake is detected because of aquaculture effluent water.

• The Korean Journal of Zoology
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• v.7 no.2
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• pp.6-12
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• 1964

The present paper deals with the changes in serum protein fraction, total serum protein, hematocrit, red blood cell, haemoglobin, and weight of liver or kidney : body weight ratio of irradiated and non-irradiated snake head, Ophicephalus argus(CANTOR) . Irrardiation doses are 2537$\AA$-7 minutes (7M) and 2537$\AA$-15 minutes (15M). Serum electrophoretic patterns showed a marked decrease in albumin fraction at 1, 3, 9, 12 and 15 days on 7M group and 15 M group. On both experimental groups percentage increases in $\alpha$1 and $\beta$ fractions occurred at different time periods in general but are interpreted as only apparent changes accompanying the greater albumin fall. ${\gamma}$-Globulin decreased at 1, 6 and 15 days on 7M group. and at 1, 3, 6 and 9 days on 15M group. Also, A/G ratio was significantly low in groups subjected to above conditions as compared to the controls. A/G ratio decreased at 3 and 15 days remarkably on both groups. On the average, the reductions in the A/G ratio were not proportional to themagnitude of ultraviolet-light. Total protein of serum changed according to suggestive changes in electrophoretic patterns of serum . Total protein of serum declined at 1, 3, 6, 9 and 12 day periods on 7M groups and at 1, 3, 9, 12 and 15 day-periods on 15 M group, and increased approaching control values at 15 and 18 day-periods on both groups. Hematocrit increased remarkably at 1, 3, 6 and 12 days and decreased at 9 and 15 days on 7M group, and increased throughout the sampling period on 15M . Red blood cell decreased throughout the sampling period and increased slightly at 6 days on 7 M group and decreased at 1, 6, 9, 15 and 18 days and increased remarkably at 3 and 12 days on 15M group. Hemoglobin decreased remarkably at 1 day-period and increased at other days on both groups. The liver weight was not remarkably changed after whole body irradiation on both groups. and kidney was increased from 1st day on 7M group and 3 rd day on 15M group respectively. It appears that changes in electropphoretic patterns of serum, A/G ratio, total protein of serum, hematocrit, red blood cell, hemoglobin, and liver or kidney weight act to the detriment of the animal following non-ionizing irradiation.

• Ocean Science Journal
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• v.41 no.1
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• pp.11-29
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• 2006

We investigated species composition and spatial distribution of the euphausiid community in the Yellow Sea and identified the relationship with environmental factors (temperature, salinity, chlorophyll $\alpha$, nitrate, phosphate, and silicate) using bimonthly data from June, 1997 to April, 1998. The environment varied during the sampling period. In warm seasons, thermocline was well developed rendering lower temperature and higher salinity and nutrient concentrations in the bottom layer. During cold seasons the water column was well mixed and no such vertical stratification was noted. Horizontal distribution of temperature, however, differed slightly between near-coast and offshore areas because of the shallow depth of the Yellow Sea, and between southern and northern areas because of the intrusion of water masses such as Yellow Sea Warm Current and Changjiang River Diluted Water. Four euphausiid species were identified: Euphausia pacifica, E. sanzoi, Pseudeuphausia sp. and Stylocheron affine. E. sanzoi and S. affine were collected, just one juvenile each, from the southern area in June and December, respectively. Pseudeuphausia sp. were collected in the eastern area all the year round except June. E. pacifica occurred at the whole study area and were the predominant species, representing at least 97.6% of the euphausiid abundance. Further, the distribution pattern of the species was varied in regards to developmental stages (adult, furcilia, calyptopis, egg). From spring to fall, E. pacifica adults were abundant in the central area where the Yellow Sea Bottom Cold Water prevailed. Furcilia and calyptopis extended their distribution into nearly all the study area during the same period. From late fall to winter, adults were found at the near-coastal are a with similar pattern for furcilia and calyptopis. The distribution pattern of E. pacifica was consistent regarding temperature, salinity, and three nutrients during the sampling period, whereas chlorophyll $\alpha$ showed a different pattern according to the developmental stages. The nutrients should indirectly affect via chlorophyll $\alpha$ and phytoplankton concentration. With respect to these results, we presented a scenario about how the environmental factors along with the water current affect the distribution of E. pacifica in the Yellow Sea.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.626-637
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• 2018

In this study, a series of survey were conducted to identify the distribution patterns of macrobenthos at the Bongam sand tidal flat in Masan Bay. We collected macrobenthos at 9 sampling sites twice in June and September of every year from 2012 to 2017 using a box core sampler (collecting area, $0.025m^2$). There was a total of 50 species with a community density of $6,388ind.m^{-2}$ and a biomass of $313.9g\;wet\;m^{-2}$ during the study period. Polychaetes had the highest number of species and density among the macrofauna, but the mollusks had the largest biomass. The number of species ranged from 10 to 25 during study period but increased to over 20 species in 2014. The density which ranged from $1,508ind.m^{-2}$ to $12,008ind.m^{-2}$ rapidly increased in 2015. The dominant species were all polychaetes such as Heteromastus filiformis, Prionospio japonicus, Hediste diadroma, and Neanthes succinea. The mean diversity index ranged from 1.2 to 1.9, richness index from 1.2 to 2.4, and evenness index from 0.5 to 0.9. From the cluster analysis results, there was a spatial difference in the similarity of faunal composition of macrobenthos and this pattern was maintained throughout the study period, that is, the temporal similarities were higher than the spatial similarities. There was a change in community composition from June 2014 to June 2015 in most of the sampling sites. During this time, the dominant species also changed from H. filiformis and N. succinea to H. filiformis and H. diadroma. The density of opportunistic species such as Capitella capitata and Polydora ligni decreased compared to the early 2000s while the population of H. diadroma increased from 2015. There was little ecological information on H. diadroma such as when and where this species occurred.