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Variability Characteristics Analysis of the Long-term Wind and Wind Energy Using the MCP Method (MCP방법을 이용한 장기간 풍속 및 풍력에너지 변동 특성 분석)

  • Hyun, Seung-Gun;Jang, Moon-Seok;Ko, Suk-Hwan
    • Journal of the Korean Solar Energy Society
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    • v.33 no.5
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    • pp.1-8
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    • 2013
  • Wind resource data of short-term period has to be corrected a long-term period by using MCP method that Is a statistical method to predict the long-term wind resource at target site data with a reference site data. Because the field measurement for wind assessment is limited to a short period by various constraints. In this study, 2 different MCP methods such as Linear regression and Matrix method were chosen to compare the predictive accuracy between the methods. Finally long-term wind speed, wind power density and capacity factor at the target site for 20 years were estimated for the variability of wind and wind energy. As a result, for 20 years annual average wind speed, Yellow sea off shore wind farm was estimated to have 4.29% for coefficient of variation, CV, and -9.57%~9.53% for range of variation, RV. It was predicted that the annual wind speed at Yellow sea offshore wind farm varied within ${\pm}10%$.

Effect of Light Conditions on the Seasonal Growth and Photosynthetic Ability in Several Wintergrasses (광환경의 차이가 한지형 잔디의 연중 생육 및 광합성 능력에 미치는 영향)

  • 허건양
    • Asian Journal of Turfgrass Science
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    • v.11 no.4
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    • pp.271-280
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    • 1997
  • The short green period of zoysiagrass has been a problem in using for turf. This study was performed to check growth response of several wintergrasses under sunny and shady area in Korea. Wintergrasses of 5 species, 27 cultivars introduced from U.S.D.A., were used in this study. After establishment, two fluctuations of top growth were observed which varied according to the species; first, due to drought in May, second, due to high temperature and humidity from July to August. Red fescues and perennial ryegrasses showed severe growth retardation in sunny area during summer period. Kentucky bluegrasses and tall fescues maintained good Qualities nearly all the year round arid showed slight disease infections. Kentucky bluegrass 'Kenblue' and red fescue 'Agram' grown under shady area showed higher photosynthetic ability than under sunny area, except the temperature range from 30˚C to 40 ˚C under 40,000 lux light in red fescue 'Agram'. And the phorosynthesis was decreased at the temperature range from 35 ˚C to 40 ˚C. Key words: Wintergrass, Top growth, Visual rating, Photosynthesis, Poa pratensis. Festuca arundinacea, Pestuca rubra. Lolium perenne, Agrostis stolonifera.

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Analysis of Changes in Home Management Part in Home Economics Textbooks for Middle School (교육과정 시기에 따른 중학교 가정교과서 가정관리분야 단원의 변천과정 분석 (I))

  • 이연숙
    • Journal of Korean Home Economics Education Association
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    • v.13 no.1
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    • pp.73-91
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    • 2001
  • The purpose of this study was to analyze the changes in home management part in the home economics textbooks for middle school from the 1st to the 7th curriculum period. The part of home management in the all of home economics textbooks published in every curriculum period was analyzed using several external criteria of textbook. The major findings of this study were as follows : 1. The part of home management was divided into even specific areas including 'definition and process of home management'. 'time management'. 'household labor/work management'. 'family financial management'.'purchasing'. and 'consumer protection'. 2. The part of home management has been included in the middle school home economics textbooks since the 1st curriculum period. The proportion of this part in the whole textbook varied with range from 5.1% to 31.8%. 3. The areas emphasized in the beginning of curriculum period were 'family financial management'and 'household labor/work management'. and 'utilization of family resource and environment management'were the areas emphasized in the later curriculum period. 4. The titles of the middle and small unit have begun to use recent words and have represented the including contents since the 4th curriculum period. 5. The numbers of illustrations. tables. pictures. and activities have increased since the 6th curriculum period. 6. Other unrelated areas such as computer and career preparation were included in the home management part in the 1st. 2nd. and 5th curriculum period.

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Analyses of Debris Flow by Heavy Rainfall of Sangnamri of Injegun in 2009 (2009년 집중호우에 의한 인제군 상남리 토석류 현장 분석)

  • Choi, Joon-Sik;Kwak, Cheol-Soo;Yoo, Nam-Jae
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.883-890
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    • 2010
  • This study is a research results about flow characteristics of debris flow mobilized from landslides such as initiation, transportation and deposition. As results of slope stability analyses at sites studied, the safety factors in rainy period are decreased drastically in comparisons with those in dry period so that the effect of rainfall on initiation of debris flow is known to be significant. From results of analyzing rainfall data, debris flow occurred as previous rainfall accumulated during 2 weeks was more than 526mm, the maximum rainfall intensity being more than 34mm/hr and the day rainfall being more than 171mm/day. As results of analyzing topology of channel debris flow running, the angle of slope where debris flow initiated was in the range of $36{\sim}39^{\circ}$. For area of channel debris flow being transporting the angle of channel was in the range of $11{\sim}36^{\circ}$. The angle of channel where debris flow started to be deposited was found to be in the range of $5{\sim}10^{\circ}$.

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Effect of poorly-compacted backfill around embedded foundations on building seismic response

  • Kim, Yong-Seok
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.549-561
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    • 2012
  • Many building foundations are embedded, however it is not easy to compact the backfill around the foundation especially for the deeply embedded ones. The soil condition around the embedded foundation may affect the seismic response of a building due to the weak contact between the soil and the foundation. In this paper, the response accelerations in the short-period range and at the period of 1 second (in the long-period range) for a seismic design spectrum specified in the IBC design code were compared considering perfect and poor backfills to investigate the effect of backfill compaction around the embedded foundation. An in-house finite-element software (P3DASS) which has the capability of horizontal pseudo-3D seismic analysis with linear soil layers was used to perform the seismic analyses of the structure-soil system with an embedded foundation. Seismic analyses were carried out with 7 bedrock earthquake records provided by the Pacific Earthquake Engineering Research Center (PEER), scaling the peak ground accelerations to 0.1 g. The results indicate that the poor backfill is not detrimental to the seismic response of a building, if the foundation is not embedded deeply in the soft soil. However, it is necessary to perform the seismic analysis for the structure-soil system embedded deeply in the soft soil to check the seismic resonance due to the soft soil layer beneath the foundation, and to compact the backfill as well as possible.

Characteristics of Wind Energy for Long-term Period (10 years) at Seoguang Site on Jeju Island (제주 서광지역에 대한 풍력에너지의 장기간 (10년) 특성)

  • Ko, Kyung-Nam;Kim, Kyoung-Bo;Huh, Jong-Chul
    • Journal of the Korean Solar Energy Society
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    • v.28 no.3
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    • pp.45-52
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    • 2008
  • In order to clarify characteristics of variation in wind energy over a long-term period, an investigation was carried out at Seoguang site on Jeju island. The wind data for 10 years from Automatic Weather System (AWS) were analyzed for each year. The variation in the annual energy production (AEP) for the 2 MW wind turbine was estimated through statistical work. The result shows that the range of the yearly average wind speed at 15 m above ground level for 10 years was from -22.6% to +13.7%, which is wider range than that in Japan. The coefficient of variation for the AEP was 22.7%, which is about twice of that for the yearly average wind speed. Therefore, for estimating the wind energy potential accurately at a given site, the wind data should be analyzed over a long-term period based on the data from the meteorological station.

Evaluation of Acid Rain through the Scavenging Theory and Application of Trajectory Model (세정이론을 통한 산성비의 평가와 발원지 추적)

  • Kim, Jeong-Soo;Kang, In-Goo;Chang, Sung-Kee
    • Journal of Korean Society for Atmospheric Environment
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    • v.8 no.2
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    • pp.121-127
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    • 1992
  • This study was carried out to investigate the features of air pollutants in rainwater and trace their transported trajectories from other countries. Chemical analysis data of rainwater and suspended particulates collected at Seoul, Kanghwa, and Taean for three years were used to evaluate the effects of long-range transport of air pollutants. Scavenging theory on washout and rainout effect during a rainy period was applied to estimate whether pollutants in the precipitation were long-range transported or not. On the other hand, precipitation weighted surface wind were evaluated to analyze the effect from local sources on atmospheric concentrations. As a result, contribution of air pollutants caused by anthropogenic sources in the precipitation which was identified to be long range transported was confirmed significantly high and trajectory of these pollutants was to be equivalent to 850mb isobar. Although concentration of acidifying components increased in the precipitation, neutralization by alkaline soil components such as $Ca^{2+}$ and $Mg^{2+}$ was conspicuous especially during Yellow-sand period.

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Korean Medicine Treatment for 326 patients with Genital Warts : Retrospective Chart Review (성기사마귀환자 326명의 한의학적 치료에 대한 후향적 연구)

  • Lee, Kyoung-Yeob;Lee, Eun;Cho, Nae-Kyoung
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.28 no.4
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    • pp.196-207
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    • 2015
  • Purpose : To observe effects of Korean Medicine treatment for genital warts.Methods : In a single private clinic from February 2014 to February 2015, we did retrospective chart review for 326 patients with genital warts who had been treated by Korean Medicine. Korean Medicine treatment included herbal treatment and herbal ointment.Results : A total of 326 patients were enrolled in this study: 62.7%(n=219) male, 32.8%(n=107) female. In the type of diagnosis, new diagnosis was 45.4%(n=148) and recurrent disease was 54.6%(n=178). Complete clearance was achieved 63.2%(n=206) and treatment period was 3.5 months(range:1-9). Partial clearance-good was 15%(n=49), partial clearance-poor was 4.9%(n=16), non response was 16.9%(n=55) and the average treatment period was 4.3 months(range:1-14). In complete clearance group, female and the prevalence of less than 1 year were statistically significant(p<0.05). There was no recurrence of genital warts after TKM treatment during follow-up period(4-13months).Conclusion : This study suggest that Korean Medicine may be an effective treatment for genital warts.

Can Breast Asymmetry Following the Treatment of Juvenile Idiopathic Scoliosis with Growing Rod Be Prevented? : A Preliminary Analysis

  • Atici, Yunus;Polat, Baris;Erdogan, Sinan;Gurpinar, Tahsin;Demiroz, Serdar
    • Journal of Korean Neurosurgical Society
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    • v.63 no.2
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    • pp.228-236
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    • 2020
  • Objective : It can be assumed that the progression of scoliosis in the juvenile period will increase the asymmetry in the rib cage, and thus will contribute to an increase in the breast asymmetry (BA) in the future. We are looking for answers to the questions; "How will the breasts look with respect to each other and what is the possibility of developing BA in the early follow-up period following the early surgical treatment and final fusion surgery of juvenile idiopathic scoliosis (JIS)?" For this reason, in this study, we aimed to evaluate the breast asymmetries of patients in the period after the final fusion. Methods : Following growing rod treatment, final fusion was achieved in 12 females with JIS. We used the anthropomorphic measurement of the modified BREAST-V formula to assess whether there was an asymmetry between the breasts after an average of 4.8 years (2-11) following final fusion. Results : In comparison, the mean volume of the left breast (222.4 mL [range, 104.1-330.2]) was larger than the mean volume of the right breast volume (214.5 mL [range, 95.2-326.7]) (p=0.034). The left breast was larger in 75% of the patients. BA was observed in 50% of the patients. No correlation was detected between the Cobb angle of the patient after final fusion and BA (p=0.688). Conclusion : In the late follow-up period, BA was detected in 50% of the patients with JIS who achieved final fusion after treatment with growing rod. In majority of the patients, left breast was larger. The patients with JIS and their families can be informed prior to the operation about the probability of BA seen in the follow-up period after fusion.

Taste Components and Sensory Characteristics of Long-term Mature Korean Soy Sauce (장기 숙성된 한식간장의 맛성분 및 관능적 특성)

  • Jang, Hyeock-soon;Lee, Nan-Hee;Choi, Ung-Kyu
    • The Korean Journal of Food And Nutrition
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    • v.32 no.4
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    • pp.349-354
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    • 2019
  • In this study, 30 kinds of long-term and mature Korean soy sauce were collected and classified by the fermentation period, and the components related to taste and sensory characteristics were analyzed. A total of 4 kinds of organic acids were detected. The total organic acid content was in the range of 97.2~341.6 mg%, but did not show the tendency to increase or decrease in proportion to the aging period. The total free amino acid content was within the range of 3,001.0~3,834.7 mg% and showed a tendency to increase in proportion to the ripening period of the soy sauce. The contents of aspartic acid and glutamic acid subsequently increased in the long-term matured soy sauce. The ratio of essential amino acid to total amino acid was 31.6~35.7%, and the ratio of glutamic acid to total amino acid was 19.6~23.9%, respectively. The panel of 20~29-year-old indicated that the longer the aging period of soy sauce, the lower the preference while the panel of 30 or more years indicated that the longer the aging period of soy sauce, the higher the preference. This study was the first to investigate the quality of long-term matured soy sauce in more than one year.