• Title/Summary/Keyword: Power quality measurement

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A Study on the Characteristics of PM1.0 Chemical Components Using a Real-time Aerosol Mass Spectrometer (실시간 에어로졸 질량분석기를 이용한 PM1.0의 화학적성분의 특성에 관한 연구)

  • Park, Jinsoo;Choi, Jinsoo;Kim, Hyunjae;Oh, Jun;Sung, Minyoung;Ahn, Joonyoung;Lee, Sangbo;Kim, Jeongho
    • Journal of the Korean Society of Urban Environment
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    • v.18 no.4
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    • pp.485-494
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    • 2018
  • This study aims to identify the characteristics of oxidation and chemical composition of PM in winter season, 2017 at Incheon area. The mean concentration of air pollutants were $46{\pm}22{\mu}g/m^3-PM_{10}$, $29{\pm}18{\mu}g/m^3/-PM_{2.5}$, $5{\pm}3ppb-SO_2$, $0.56{\pm}0.24ppm-CO$, $21{\pm}13ppb-O_3$ and $28{\pm}17ppb-NO_2$, respectively. The dominant ion of the $PM_{1.0}$ chemical component were organic with $3.2{\mu}g/m^3$ and nitrate with $1.9{\mu}g/m^3$. The day and night variation of the $PM_{1.0}$ chemical components was higher in nighttime than those of daytime. The averaged nitrate oxidation rate (SOR) was 0.06 and sulfate oxidation rate was 0.11 during the field campaign. In the high mass loading period, nitrate oxidation rate (NOR) was up to 0.6 and also the nitrate in $PM_{1.0}$ was increased. The averaged ratio of $NO_x/SO_2$ was 8.7 and nitrate/sulfate was 3.1, respectively. In this results, the nitrate component in $PM_{1.0}$ was influenced by NOx from the stationary source as power plant and the mobile source around the measurement site.

Development of the scale for recognition measurement of Home Economics Subject (가정교과의 인식 측정을 위한 척도 개발 연구)

  • Baek, Min-Kyung;Wang, Seok-Soon
    • Journal of Korean Home Economics Education Association
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    • v.24 no.2
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    • pp.101-116
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    • 2012
  • The purpose of this research is to develop a scale to measure how students and parents, who are the consumers of education, and home economics teachers and education experts, who are the suppliers, recognize the home economics subject, based on the characteristics and goal of the revised home economics curriculum that is currently being applied in South Korea, in the year 2007. To do this, the survey on home economics recognition developed and utilized in prior researches was used as the basic data. The final version of 60 questions was made by adding questions made through steps. They include question quality factor verification through step1-interview, step2-draft questions, step3-preliminary research, and step4-substantiation research of four groups. As a result of the factor analysis of the recognition of home economics, credibility is high in all factors. The final scale consists of 8 factors, when the explanatory power is 57.439%. This shows that home economics has been established as education for living and a practical subject. Nevertheless, it needs further improving to be recognized as a subject involving emphasis on healthy formation of family life and a subject of practical criticism.

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Development of Ocean Data Buoy and Real-Time Monitoring Technology (종합관측부이 개발 및 실시간 관측기술)

  • 심재설;이동영;박우선;박광순
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.11 no.1
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    • pp.56-67
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    • 1999
  • It is desired to use a domestically manufactured ocean data buoy for the long-term operational ocean monitoring. The ocean data buoy manufacturing technology was introduced through the research cooperation with the Qingkong University of Taiwan. The introduced ocean data buoy system was further expanded and improved for more efficient application for the marine environmental monitoring in Korea. The size of the ocean data buoy is 2.5 m in diameter, which is smaller compared to the NOAA's 3.0 m discus buoy to allow easy land transportation and ocean deployment as well. From the dynamic response test of the buoy carried out numerically, it was shown that the measurement of waves with period greater than 4 seconds is acceptable. The measurement and control system of the data buoy were improved to increase the number of measuring parameters, to reduce power consumption and to enhance better data analysis and management. Each component of the improved data buoy system was described in detail in this paper. Water quality sensors of water temperature, salinity, DO, pH and turbidity were added to the system in addition to the marine meteorological sensors of wind speed and direction, air temperature, humidity, air pressure and wave. Inmarsat satellite communication system is used for the real-time data telemetry from the buoy deployed offshore. A field performance test of the improved and domestically manufactured buoy was carried out for a month at the open sea off Pohang together with DatawelI's Wave-rider buoy to compare the wave data. The results of the test were satisfactory.

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Performance Evaluation of an Electrometer for Quality Control and Dosimetry in Radiation Therapy (방사선 치료의 정도관리 및 선량측정에 이용되는 전리계의 성능평가)

  • Kim, Chang-Seon;Kim, Chul-Yong;Park, Myung-Sun
    • Progress in Medical Physics
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    • v.11 no.2
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    • pp.123-130
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    • 2000
  • The performance of an electrometer directly affects on the accuracy and precision in radiation dosimetry. This study is to list of the quality control for maintaining performance and to perform evaluation tests of an electrometer. Performance tests selected include proper polarizing voltages, warm-up and equalization time, leakages, long-term stability, linearity, and effect of ambient conditions. An electrometer connected with a rigid stem ionization chamber was evaluated with a Strontium-90 check device. Bias voltage was measured directly on the input socket. Equalization time is the time required for reaching threshold of charged state after the power is on or the bias voltage is changed. Pre- and post-signal leakages are defined as the accumulation of signal with no exposure and after exposure, respectively. Over three months period, the electrometer's long-term stability was measured by comparison of the temperature-pressure corrected readings. Linearity was expressed as the deviation of readings from multiple short exposures from one continuous exposure. Effect of ambient conditions was expressed as the zero drift of the electrometer over 17-34$^{\circ}C$ temperature ranges. For two nominal values, 300 and 500 volts, measured voltages were lower by 2.5 and 5.8%, respectively. The warm-up time, 20 minutes, was longer than the lamp time by 9 minutes and the equalization time was less than 1 minute. Without exposure, the zero-drift was 0.002 scale-unit in 15 minutes and the leakage after 10 minutes exposure was minimal. The IQ-4 was stable over 99.4% for three-month periods. Deviation from the linearity was 0.9% for measurement scale, 0.000-9.991. Over 17-34$^{\circ}C$ temperature range, the zero-drift was minimal, less than 0.2%. For a clinically-used electrometer, a list for the basic peformance evaluations is proposed. By running this program, the measurement error using an electrometer can be reduced and in turn the improvement in accuracy and precision of radiation dosimetry can be achieved.

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Keyhole Imaging Combined Phase Contrast MR Angiography Technique (Keyhole Imaging기법을 적용한 위상대조도 자기공명 혈관조영기법)

  • Lee, D.H.;Hong, C.P.;Han, B.S.;Lee, M.W.
    • Journal of Biomedical Engineering Research
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    • v.33 no.2
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    • pp.72-77
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    • 2012
  • Phase Contrast MR Angiography(PC MRA) is excellent MRA technique for measuring the velocity of vessels in the human body. PC MRA need to at least four images for angiogram reconstruction and it caused longer scan time. Therefore, we used keyhole imaging combined PC MRA to reduce the scan time. However, keyhole imaging can lead the erroneous effects as loss of phase information or frequency discontinuous. In this study, we applied the keyhole imaging combined 2D PC MRA for improving the temporal resolution and also measured the velocity to evaluate the accuracy of phase information. We used 0.32T MRI scanner(Magfinder II, Scimedix, Korea). Using the 2D PC MRA pulse sequence, the vascular images for a human brain targeted on the Superior Sagittal Sinus(SSS) were obtained. We applied tukey window function for keyhole images to minimize the ringing artifact and erroneous factors that are induced frequency discontinuous and phase information loss. We also applied zero-padded algorithm to peripheral missing k-space lines to compare keyhole imaging results and the artifact power(AP) value was measured on the complex difference images to validate the image quality. Consider as based on our results, heavy image distortions and artifacts were shown until using at least 50% keyhole factor. Using above the 50% keyhole factors are shown well reconstructed and matched for magnitude images and velocity information measurements. In conclusion, we confirmed the image quality and velocity information of keyhole technique combined 2D PC MRA. Especially, measured velocity information through the keyhole imaging combination was similar to the velocity information of full sampled k-space image despite of frequency discontinuous and phase information loss in the keyhole imaging reconstruction process. Consequently, the keyhole imaging combined 2D PC MRA will give some clinical usefulness and advantages as improving the temporal resolution and measuring the velocity information via selecting the appropriate keyhole factor at low tesla MRI system.

Predictors of Psychological Happiness in Leisure Sports Participant - Focusing on Amateur Baseball Clubs - (여가스포츠 참여자의 심리적 행복감 예측요인 - 사회인 야구를 중심으로 -)

  • Suh, Hae-Joo;Kim, Ja-Ok;Kim, Ja-Sook;Kim, Hack-Sun;Park, A Young
    • Journal of Digital Convergence
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    • v.16 no.1
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    • pp.409-420
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    • 2018
  • This is a convergence study to investigate the factors affecting the psychological happiness of leisure sports participants(social baseball club) and to present a strategy for effective program development. The subjects of this study were 151 participants of social baseball clubs in J-do area and collected data by self-reported questionnaire. Data were analyzed by descriptive statistics, t-test, ANOVA, correlation analysis and stepwise multiple regression analysis. The results of this study were the explanatory power was 54.1% with psychological happiness, quality of life, self-efficacy. As a result, it was confirmed that strengthening interpersonal relationship ability, positive reinforcement of self-efficacy, and quality of life were important for improvement of psychological happiness. and in the future, it is necessary to study repeatedly to confirm the influence of psychological through objective measurement.

Mechanical Characteristics and Preferences of Gamkugsulgie-dduk by Different Addition of Chrysanthemum indicum L. (감국의 첨가에 따른 감국 설기떡의 품질 특성과 기호도)

  • 박금순;신영자
    • Journal of the East Asian Society of Dietary Life
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    • v.8 no.3
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    • pp.289-296
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    • 1998
  • The quality of physical characteristics were measured, using sensory evaluation and mechanical characteristics where different percentages of chrysanthemums (0%, chrysanthemum indicum power: 1%, 3% and 5%, and Chrysanthemum indicum petals: 1%, 3% and 5%) were added to rice flour, to promote the use of and liking forrice cakes that are a kind of Korean traditional foods. In the sensory evaluation, the color appeared to be the highest when 3% of Chrysanthemum indicum petals was added, and there was a significant difference between the samples used(p<.01). It was also shown that the taste was generally higher in steamed, Gamkugsulgie-dduk added Chrysanthemum indicum than those in which no Chrysanthemum indicum were added, and that it appeared to be the highest, particularly, in rice cakes that 3% of Chrysanthemum indicum petals. However there was no significant difference between the samples. The Chewiness was the highest in rice cakes to Which 3% of Chrysanthemum indicum petals was added but there was no significant difference between the samples. The after-swallow feeling and overall quality were the highest in rice cakes to which 3% of Chrysanthemum indicum petals(p<.01), and there was a significant difference between the samples(p<.01). In terms of change in color, the value of lightness was the highest in rice cakes to which no Chrysanthemum were added. The more the content of Chrysanthemums, the lower the value of lightness but the higher the values of red color(a) and yellow color(b). In the measurement of the texture, using a mechanical characteristics, the springiness was the highest in rice cakes to which 5% of Chrysanthemum indicum powder was added, and the gumminess, hardness and chewiness appeared to be high in rice cakes to which 5% of Chrysanthemum indicum petals was added. In the correlation between the sensory evaluation and mechanical characteristics, the higher the softness, the lower the value of lightness. The softness in the sensory evaluation showed a positive correlation with the values of red color(a) and yellow color(b) in the color test. the chewiness in the sensory evaluation showed a negative correlation with the springness in the mechanical characteristics. In view of the results stated above, a good recipe for steamed, Gamkugsulgie-dduk appeared that the contents of the ingredients used were 291g of rice flour, 9g of Chrysanthemum indicum petals(3% of rice flour) , 30g of sugar, and 3g of sat, 60ml of water.

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Changes of Functional Compounds in, and Texture Characteristics of, Apples, during Post-Irradiation Storage at Different Temperatures (감마선 조사와 저장온도에 따른 사과의 기능성 성분 및 조직감 변화)

  • Yun, Hye-Jeong;Lim, Sang-Yong;Hur, Jung-Mu;Jeong, Jin-Woo;Yang, Soo-Hyung;Kim, Dong-Ho
    • Food Science and Preservation
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    • v.14 no.3
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    • pp.239-246
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    • 2007
  • The effects of gamma irradiation on the physiochemical and physical characteristics of apples were investigated during post-irradiation storage at $4^{\circ}C\;and\;25^{\circ}C$. The contents of total and reducing sugars were analyzed and the results indicated that apples receiving 1 kGy of gamma irradiation did not show significant differences in sugar contents compared to non-irradiated controls. Important physiological characteristics were evaluated by measurement of total phenolic content and total flavonoid content, reducing power, and radical scavenging ability, and the results indicated that gamma irradiation at a dose of 1 kGy did not affect physiological activities. Changes in physical parameters such as weight loss, strength, cohesiveness and hardness, during post-irradiation storage, were temperature-dependent, whether the apples were irradiated or not The color and sensory acceptance of the apples were not affected by irradiation during cold storage. However, minor deterioration in color quality and sensory acceptance of irradiated apples was noted under ambient temperature storage. We conclude that gamma irradiation(1 kGy) does not affect apple nutritional content stability, functional properties, or physical characteristics, especially upon cold storage after radiation treatment.

An Operations Study on a Home Health Nursing Demonstration Program for the Patients Discharged with Chronic Residual Health Care Problems (추후관리가 필요한 만성질환 퇴원환자 가정간호 시범사업 운영 연구)

  • 홍여신;이은옥;이소우;김매자;홍경자;서문자;이영자;박정호;송미순
    • Journal of Korean Academy of Nursing
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    • v.20 no.2
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    • pp.227-248
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    • 1990
  • The study was conceived in relation to a concern over the growing gap between the needs of chronic patients and the availability of care from the current health care system in Korea. Patients with agonizing chronic pain, discomfort, despair and disability are left with helplessly unprepared families with little help from the acute care oriented health care system after discharge from hospital. There is a great need for the development of an alternative means of quality care that is economically feasible and culturally adaptible to our society. Thus, the study was designed to demonstrate the effectiveness of home heath care as an alternative to bridge the existing gap between the patients' needs and the current practice of health care. The study specifically purports to test the effects of home care on health expenditure, readmission, job retention, compliance to health care regime, general conditions, complications, and self-care knowledge and practices. The study was guided by the operations research method advocated by the Primary Health Care Operations Research Institute(PRICOR) which constitutes 3 stages of research : namely, problem analysis solution development, and solution validation. The first step in the operations research was field preparation to develop the necessary consensus and cooperation. This was done through the formation of a consulting body at the hospital and a steering committee among the researchers. For the stage of problem analysis, the Annual Report of Seoul National University Hospital and the patients records for last 5 years were reviewed and selective patient interviews were conducted to find out the magnitude of chronic health problems and areas of unmect health care needs to finally decide on the kinds of health problems to study. On the basis of problem analysis, the solution development stage was devoted to home care program development asa solution alternative. Assessment tools, teaching guidelines and care protocols were developed and tested for their validity. The final stage was the stage of experimentation and evaluation. Patients with liver diseases, hemiplegic and diabetic conditions were selected as study samples. Discharge evaluation, follow up home care, measurement and evaluation were carried out according to the protocols of care and measurement plan for each patient for the period of 6 months after discharge. The study was carried out for the period from Jan. 1987 to Dec. 1989. The following are the results of the study presented according to the hypotheses set forth for the study ; 1. Total expenditures for the period of study were not reduced for the experimental group, however, since the cost per hospital visit is about 4 times as great as the cost per home visit, the effect of cost saving by home care will become a reality as home care replaces part of the hospital visits. 2. The effect on the rate of readmission and job retention was found to be statistically nonsignificant though the number of readmission was less among the experimental group receiving home care. 3. The effect on compliance to the health care regime was found to be statistically significant at the 5% level for hepatopathic and diabetic patients. 4. Education on diet, rest and excise, and medication through home care had an effect on improved liver function test scores, prevention of complications and self - care knowledge in hepatopathic patients at a statistically significant level. 5. In hemiplegic patient, home care had an effect on increased grasping power at a significant level. However. there was no significant difference between the experimental and control groups in the level of compliane, prevention of complications or in self-care practices. 6. In diabetic patients, there was no difference between the experimental and control groups in scores of laboratory tests, appearance of complications, and self-care knowledge or self -care practices. The above findings indicate that a home care program instituted for such short term as 6 months period could not totally demonstrate its effectiveness at a statistically significant level by quantitative analysis however, what was shown in part in this analysis, and in the continuous consultation sought by those who had been in the experimental group, is that home health care has a great potential in retarding or preventing pathological progress, facilitating rehabilitative and productive life, and improving quality of life by adding comfort, confidence and strength to patients and their families. For the further studies of this kind with chronic patients it is recommended that a sample of newly diagnosed patients be followed up for a longer period of time with more frequent observations to demonstrate a more dear- cut picture of the effectiveness of home care.

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Effects of Mindfulness Based Stress Reduction Program on Depression, Anxiety and Stress in Patients with Aneurysmal Subarachnoid Hemorrhage

  • Joo, Hye-Myung;Lee, Sung-Jae;Chung, Yong-Gu;Shin, Il-Young
    • Journal of Korean Neurosurgical Society
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    • v.47 no.5
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    • pp.345-351
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    • 2010
  • Objective : In this study, the Mindfulness Based Stress Reduction (MBSR) program was applied to patients presenting with depression and anxiety after surgery from spontaneous subarachnoid hemorrhage (SAH) and the effects were assessed. Methods : The subjects were patients admitted for cerebral aneurysm rupture and treated by means of surgery from March to December, 2007. More than 6 months had passed after surgery, without any special lesions showing up on computed tomography (CT), and the Glasgow outcome scale (GOS) was 5 points. Among patients with anxiety and depression symptoms, 11 patients completed the program. The MBSR program was conducted once a week, 2.5 hours each, for 8 weeks. The evaluation criteria were : 1) the Beck Depression Inventory (BDI): it measures the type and level of depression, 2) the State-Trait Anxiety Inventory : the anxiety state of normal adults without mental disorder, and 3) Heart Rate Variability (HRV) : the influence of the autonomous nervous system on the sinoarterial node varies continuously in response to the change of the internal/external environment. Results : The BDI value was decreased from 18.5 ${\pm}$ 10.9 to 9.5 ${\pm}$ 7.1 (p = 0.013) : it was statistically significant, and the depression level of patients was lowered. The state anxiety was decreased from 51.3 ${\pm}$ 13.9 to 42.3 ${\pm}$ 15.2; the trait anxiety was reduced from 50.9 ${\pm}$ 12.3 to 41.3 ${\pm}$ 12.8, and a borderline significant difference was shown (p = 0.091, p = 0.056). In other words, after the treatment, although it was not statistically significant, a decreased tendency in anxiety was shown. In the HRV measurement, standard deviation normal to normal (SDNN), square root of the square root of the mean sum of squared differences between adjacent normal to normal intervals (RMSSD), and total power (TP) showed significant increase, Physical Stress Index (PSI) showed a significant reduction, and thus an improvement in the homeostatic control mechanism of the autonomic nervous system was ween. Conclusion : The MBSR program was applied to the patients showing anxiety and depression reaction after SAH treatment, and a reduction in depression symptoms and physiological reactions were observed. The application of the MBSR program may be considered as a new tool in improving the quality of life for patients after surgery.