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A Comparative Study of Elementary School Mathematics Textbooks between Korea and Japan - Focused on the 4th Grade - (한국과 일본의 초등학교 수학교과서 비교 연구 - 4학년을 중심으로 -)

  • Lee, Jae-Chun;Kim, Seon-Yu;Kang, Hong-Jae
    • Journal of Elementary Mathematics Education in Korea
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    • v.13 no.1
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    • pp.1-15
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    • 2009
  • This research is to provide a useful reference for the future revision of textbook by comparative analysis with the textbook in the 4th grade of elementary school in Japan. The results from this research is same as follows: First, Korean curriculum is emphasizing the reasonable problem-solving ability developed on the base of the mathematical knowledge and skill. Meantime, Japanese puts much value on the is focusing on discretion and the capability in life so that they emphasize each person's learning and raising the power of self-learning and thinking. The ratio on mathematics in both company are high, but Japanese ensures much more hours than Korean. Second, the chapter of Korean textbook is composed of 8 units and the title of the chapter is shown as key word, then the next objects are describes as 'Shall we do$\sim$' type. Hence, the chapter composition of Japanese textbook is different among the chapter and the title of the chapter is described as 'Let's do$\sim$'. Moreover, Korean textbook is arranged focusing on present study, however Japanese is composed with each independent segments in the present study subject to the study contents. Third, Japanese makes students understand the decimal as the extension of the decimal system with measuring unit($\ell$, km, kg) then, learn the operation by algorithm. In Korea, students learn fraction earlier than decimal, but, in Japan students learn decimal earlier than fraction. For the diagram, in Korea, making angle with vertex and side comes after the concept of angle, vertex and side is explained. Hence, in Japan, they show side and vertex to present angle.

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Number of Trials for the Reliable Golf Swing Ground Reaction Force Data Collection and Its Characteristics (골프 드라이버스윙 시 지면반력 반복측정 횟수와 지면반력 특성)

  • Park, Young-Hoon;Youm, Chang-Hong;Seo, Kuk-Woong;Seo, Kook-Eun
    • Korean Journal of Applied Biomechanics
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    • v.17 no.4
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    • pp.115-125
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    • 2007
  • Grould Reaction force(GRF) is important in human movements and GRF measurements are one of the most frequently used tool in biomechanical studies. In the studies of the golf swing motion, people refer to GRF as weight transfer. A successful golf swing motion requires many segments activation sequences which are controled by the nerve system. Due to the inter- and intra-individual variability of the human movement and the movement strategies, reliability of the measurements are important in human movement studies. Previous golf researches were based on group studies and certain events' values were analyzed. The purposes of this study were to determine the number of trials for the reliable golf swing GRF data collection, to reveal the variability level of the meaningful components of the golf swing GRF, and to classify the types of the golf swing GRF patterns. Twenty three male professional golfers($26.4{\pm}6.6$ years, $174.3{\pm}5.2\;cm$, $71.3{\pm}6.5\;kg$) signed an informed consent form prior to participation in this study. GRFs of driver swings were collected with Kistler 9285 force platform and 9865A amplifier, and calculated by the KwonGRF program(Visol, Korea). Sampling frequency was 1080 Hz. GRF data were trimmed from 1.5 s prior to the impact to 0.5 s after the impact. The number of trials for the reliable GRF collection was determined when the change in floating mean overs the 25 % of the standard deviation of that variable. Variabilities of the variables were determined by the coefficient of variation(CV) of 10 %. The types of GRF patterns were determined by visual inspection of the peak GRF shapes. The minimum number of trials for the reliable golf swing GRF data collection was five. Ten-trial seems more conservative. The value of the peak GRF was more reliable than the value of the impact GRF. The CV of the peak GRF and impact GRF were 7.4 %, 15.2 %, respectively. Because of the +/- sigh of the peak GRF appearance time, it was impossible to calculate CV of the peak GRF appearance time. Golf swing GRF patterns were classified as sing peak type, double peak type, and plateau peak type. This classification suggests the presence of the different golf swing weight transfer strategies.

Methodology for Calculating Surrogate Safety Measure by Using Vehicular Trajectory and Its Application (차량궤적자료를 이용한 SSM 산출 방법론 개발과 적용사례 분석)

  • PARK, Seongyong;LEE, Chungwon;KHO, Seung-Young;LEE, Yong-Gwan
    • Journal of Korean Society of Transportation
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    • v.33 no.4
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    • pp.323-336
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    • 2015
  • Estimating the risks on the roadway using surrogate safety measures (SSM) has an advantage in that it focuses on the vehicle trajectory directly involved in conflicts. On the other hand, there is a restriction on estimating the risks of continuous segments due to the limited data collected from a location. To overcome the restriction, this study presents the scheme of acquiring the vehicular trajectory using real time kinematics-differential global positioning system (RTK-DGPS) and develops a methodology which contains the considerations of the problems to calculate the SSM such as time-to-collision (TTC), deceleration rate to avoid collision (DRAC) and acceleration noise (AN). By using the methodology, this study shows a result from an experiment executed in a section where the variation of vehicular movement can be observed from several continuous flow roadway sections near Seoul and Gyeonggi Province in Korea. The result illustrated the risks on the roadway by the SSM metrics in certain situations like merging and diverging, stop-and-go, and weaving. This study would be applied to relate the dangers with characteristics of drivers and roadway sections, and prevenst accidents or conflicts by detecting dangerous roadway sections and drivers' behaviors. This study contributes to improving roadway safety and reducing car-accidents.

Analysis of Applicability of IHSDM into Korea and User Requirements for Development of Road Design Safety Assessment System (IHSDM의 국내도로 적용성 분석 및 도로설계 안전성 평가 시스템의 사용자 요구분석)

  • Kim, Eung-Cheol;Lee, Dong-Min;Choe, Eun-Jin;Kim, Do-Hun
    • Journal of Korean Society of Transportation
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    • v.27 no.4
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    • pp.155-166
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    • 2009
  • Road design safety assessment by existing tools and methods have normally been examined by expert judgements using design documents and on-site inspections. The existing methods, however, have two main problems such as insufficiency of objectiveness and inability to measure effects of accident countermeasures. This paper studies ways to develop a road safety assessment system through reviewing the IHSDM developed in USA. The crash prediction module of IHSDM calculate accident frequency and rate of roadway segments using accident prediction models and accident modification factors for safety evaluation. The methodology of evaluation and development of accident modification factors somewhat overcome the problems of the existing methods. In spite of these advantages, IHSDM could not relevantly reflect characteristics of domestic rural roadways since it overestimate the number of accidents and rate of korean rural roadways. Especially, IHSDM may not evaluate or consider land use patterns of Korean roadways, and futhermore, original environment on base conditions used to develop IHSDM may not be different from ours. The user requirements being developed for a road safety assessment system for Korean roadways include enhanced flexibility and diversity of data input-output processes.

Study on the Effect of Jakyakgamcho-tang (작약감초탕의 효능에 관한 연구)

  • Lee Yun Suk;Kim Hyung Chang;Whang Eui Hyun;Jo Sung Kyun;Lim In Gyu;Han Jong Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.2
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    • pp.493-498
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    • 2003
  • Paeoniae Radix, Glycyrrhizae Radix and Jakyakgamchotang have been used in Oriental Medicine for many centuries as a treatment for various disease. The purpose of the present study is to determine the effect of Paeoniae Radix, Glycyrrhizae Radix and Jakyakgamchotang on narepinephrine(NE) induced contraction of isolated rabbit femoral artery. Rabbits (2.0kg, female) were killed by CO₂ exposure and a segment (8-10mm) of the aortic ring from each rabbit was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 1.5g loading tension. The dose of NE which evoked 50% of maximal response (ED/sub 50/) was obtained from cumulative dose response curves for NE (10/sup -7/~10/sup -4/M). Contractions evoked by NE (ED/sub 50/) were inhibited significantly by Paeoniae Radix, Glycyrrhizae Radix and Jakyakgamcho-tang. The mean percent inhibition of NE induced contraction was 83.9% (p<0.01) after 150㎕/㎖ Paeoniae Radix, 101.1 %(p<0.01) after 150 ㎕/㎖, Glycyrrhizae Radix and 107.3%(p<0.01) after 150㎕/㎖ Jakyakgamcho-tang, Indomethacin slightly but significantly attenuated the inhibitory effects of Paeoniae Radix. Following treatment with indomethacin, the mean percent inhibition caused by 150㎕/㎖ Paeoniae Radix fell to 16.4% in femoral artery induced by NE contraction. Propranolol, ODQ, and L-NNA did not significantly alter the inhibitory effect of Paeoniae Radix. ODQ slightly but significantly attenuated the inhibitory effects of Glycyrrhizae Radix. Following treatment with ODQ, the mean percent inhibition caused by 150㎕/㎖ Glycyrrhizae Radix fell to 13.0% in femoral artery induced by NE contraction. Propranolol, indomethacin and L-NNA did not significantly alter the inhibitory effect of Glycyrrhizae Radix. L-NNA slightly but significantly attenuated the inhibitory effects of Jakyakgamchotang. Following treatment with L-NNA, the mean percent inhibition caused by 150㎕/㎖ Jakyakgamchotang fell to 13.8% in femoral artery induced by NE contraction. Propranolol, ODQ and indomethacin did not significantly alter the inhibitory effect of Jakyakgamcho-tang. These results indicate that Paeoniae Radix, Glycyrrhizae Radix and Jakyakgamcho-tang can relax NE induced contraction of the isolated rabbit femoral artery, and that this inhibition related to nitric oxide.

Micropropagation of Juvenile and Mature Tree of Corylopsis coreana by Axillary Bud Culture (액아배양에 의한 유묘 및 성숙 히어리나무의 기내번식)

  • Moon, Heung-Kyu;Noh, Eun-Woon;Ha, Yoo-Mi;Shim, Kyung-Ku
    • Journal of Plant Biotechnology
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    • v.29 no.2
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    • pp.117-121
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    • 2002
  • We have developed an in vitro micropropagation system via shoot formation from axillary buds using nodal segments of Corylopsis coreana. Explants from both juvenile tree (one-year-old greenhouse stock seedlings) and mature tree (ten-years-old tree in nursery) were compared with regard to propagation efficiency. Combined treatment of both BA and zeatin were effective on shoot proliferation since the best result was obtained on MS medium supplemented with 0.5∼3.0 mg/L zeatin and 0.2 mg/L BA. Generally, juvenile explants were better in both shoot proliferation and growth than mature explants. However, as the duration of in vitro culture was proceed to 6 months, explants from mature tree also produced three shoots per explant. Distinctive differences in rooting and adaptability to soil of shoots obtained from mother trees. Whereas shoots originated from juvenile explants rooted as high as 97%, those from adult explants showed 62% rooting. Similar result was also observed in soil acclimatization. The plantlets derived from juvenile plants survived 67%, while only 48% of those from adult trees survived. The results showed a possibility of the micropropagation of Corylopsis coreana through shoot formation from axillary buds. In addition, the advance of the research still remain to enhance the frequency of acclimatization of plantlets from mature trees for practical application.

Expression of CP4 5-Enol-Pyruvylshikimate-3- Phosphate Synthase Transgene in Inbred Line of Korean Domestic Maize (Zea may L.) (국내 옥수수 순계주에서 CP4 5-Enol- Pyruvylshikimate-3- Phosphate Synthase 유전자의 발현)

  • Cho, Mi-Ae;Kwon, Suk-Yoon;Kim, Jin-Seog;Lee, Byoung-Kyu;Moon, Choo-Yeun;Choi, Pil-Son
    • Journal of Plant Biotechnology
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    • v.34 no.4
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    • pp.375-380
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    • 2007
  • This study was conducted to develop herbicide-resistance domestic maize plants by introducing the CP4 5-enol-pyruvylshikimate-3-phosphate synthase (CP4 EPSPS) gene using Agrobacterium tumefaciens-mediated immature embryo transformation. Immature embryos of five genotypes (HW1, KL103, HW3, HW4, HW7) were co-cultivated with strains Agrobacterium tumefaciens (strain C58C1) containing the binary vector (pCAMBIA2300) carrying Ubiquitin promoter-CP4 EPSPS gene and Cauliflower mosaic virus 35S (CaMV35S) promoter-nptll gene conferring resistance to paromomycin as a selective agent. The presence and expression of CP4 EPSPS transgene were confirmed by PCR, RT-PCR and Northern blot analysis, respectively. Also, the resistance to glyphosate in the transgenic maize ($T_1$) was analyzed by shikimate accumulation assay. The frequency (%) of paromomycin-resistance callus was 0.37, 0.03, 2.20, 2.37, and 0.81% in pure lines HW1, KL103, HW3, HW4 and HW7, respectively. EPSP transgene sequences were amplified in putative transgenic plants that regenerated from paromomycin-resistance calli of two inbred lines (HW3, HW4). Of them, RT-PCR and Northern blot analyses revealed that the transgene was only expressed in two transgenic events (M266, M104) of HW4 inbred line, and a mild glyphosate resistance of transgenic event (M266) was confirmed by the lower shikimate accumulation in leaf segments. These results demonstrate that transgenic maize with herbicide-resistance traits in Korean genotype can be genetically obtained.

In vitro shoot propagation of Ranunculus kazusensis Makino, an endangered aquatic plant (멸종위기 수생식물인 매화마름(Ranunculus kazusensis Makino)의 기내 신초 증식)

  • Park, Min Wan;Ryu, Shi Hyun;Nam, Su Hwan;Bae, Kee Hwa
    • Journal of Plant Biotechnology
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    • v.44 no.3
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    • pp.325-329
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    • 2017
  • A micropropagation method via callus for Ranunculus kazusensis Makino, an endangered species, was established. When stem segments were cultured on MS media supplemented with 1.0 mg/L IAA, NAA, IBA and 2,4-D, the highest frequency of callus induction was achieved on MS medium supplemented with 1.0 mg/L NAA. Multiple shoot per explant was obtained, the MS medium containing 1.0 mg/L BA and 0.5 mg/L NAA. Additionally, effect of activated charcoal (AC) and sucrose on shoot growth in in vitro culture were examined. The most suitable conditions for shoot growth after 4 weeks of culture were the MS medium with AC and sucrose. This in vitro propagation protocol will be valuable for conservation and mass propagation of this endangered plant.

Dose Reduction and Image Quality Assessment of the CareDose 4D Technique on Abdomen Liver Computed Tomography (복부 간 CT 검사에서 CareDose 4D 사용에 따른 선량 감소 및 화질 평가)

  • Seok, Jong-Min;Jeon, Woo-Jin;Park, Young-Joon;Lee, Jin
    • Journal of the Korean Society of Radiology
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    • v.11 no.3
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    • pp.109-115
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    • 2017
  • The purpose of this study was to evaluate the clinical efficacy of 128 MDCT (multi-detector computed tomography) for reducing the CareDose 4D dose and comparing the image quality with the fixed tube current technique. For this purpose, we conducted the phantom and clinical studies to evaluate the exposure dose and image of the subject before and after applying the CareDose 4D system in abdominal examination using 128 MDCT. In the phantom study, ROI (Region of interest) was located at the center, 3, 6, 9, 12 o'clock, into two groups: group A without CareDose 4D and Group B applied were measured. In the clinical study, ROI was located at the liver 8 segments, divided into two groups too. The measured items were CT number, noise, and dose length product (DLP) dose. The result of CTDIvol (CT Dose Index volume) measurements in phantom and clinical studies were lower than those before CareDose 4D application, and dose and effective dose were also measured lower (p<.05). There was no difference in CT number before and after application (p>.05). In conclusion, using CareDose 4D, we can obtain optimal image information without deteriorating image quality while reducing patient dose.

Effects of Suaeda asparagoides MIQ extracts on mice ileal motility (마우스 회장 운동에 대한 나문재 (Suaeda asparagoides MIQ) 추출물의 효과)

  • Song, Jae-Chan;Park, Chang-Hee;Kim, Hyun-Tak;Endale, Mehari;Rhee, Man-Hee;Park, Seung-Chun;Kim, Kil-Soo;Kim, Tae-Wan
    • Korean Journal of Veterinary Research
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    • v.46 no.4
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    • pp.323-326
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    • 2006
  • Suaeda (S.) asparagoides $M_{IQ}$, one of the halophyte groups, has been used as a folk remedy for digestive disturbances in Korea. However, its pharmacological activity on gastrointestinal motility has not been reported yet. In this study, the effects of this halophyte extracts with various solvent fractions (ethanol, hexane, chloroform, ethyl acetate, butanol, and water) on mice ileal spontaneous motility was examined. All solvent fractions at the concentration of $100{\mu}g/ml$ showed inhibitory actions on spontaneous motility of ileum with the potency order of water > 70% ethanol > hexane ${\gg}$ chloroform ${\geq}$ butanol ${\geq}$ ethyl acetate, respectively. In addition, the water fraction of extracts from S. asparagoides $M_{IQ}$ (WFSA) dose-dependently ($1-100{\mu}g/ml$) inhibited the amplitude of spontaneous phasic contraction and area under the contractile curve (AUC). The inhibitory effect of water fraction at the concentration of $10{\mu}g/ml$ was not affected by tetrodotoxin (TTX), $Na^+$ channel blocker ($1{\mu}M$), and $N^w$-nitro-L-arginine Methyl Ester (L-NAME), nitric oxide synthase inhibitor ($100{\mu}M$). However, cyclopiazonic acid (CPA, $10{\mu}M$), inhibitor of sarcoplasmic reticulum $Ca^{2+}$-ATPase, almost blocked the inhibitory effects of WFSA ($10{\mu}g/ml$) on the spontaneous phasic contraction of mouse ileum. But, CPA did not inhibit the lowering basal tone effects of WFSA. The result of this study showed that various extracts of S. asparagoides $M_{IQ}$ induce inhibitory effects on spontaneous contraction of mice ileal segments. More over, the polar solvent fractions were shown to be more potent than non-polar solvent fractions. The effects of S. asparagoides $M_{IQ}$ extracts are not mediated by nerve or nitric oxide. The inhibitory effects of WFSA at least partially mediated by sarcoplasmic reticulum $Ca^{2+}$-ATPase. However, further study is required to determine the exact pharmacological mechanisms of this halophyte on its gastrointestinal motility inhibitory effects.