• Title/Summary/Keyword: Center of Pressure

Search Result 4,966, Processing Time 0.047 seconds

Dynamics of Barrel-Shaped Young Supernova Remnants (항아리 형태 젊은 초신성 잔해의 동력학)

  • Choe, Seung-Urn;Jung, Hyun-Chul
    • Journal of the Korean earth science society
    • /
    • v.23 no.4
    • /
    • pp.357-368
    • /
    • 2002
  • In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

Vulnerability Assessment on Spring Drought in the Field of Agriculture (농업지대 봄 가뭄에 대한 취약성 평가)

  • Lee, Yong-Ho;Oh, Young-Ju;Na, Chae-Sun;Kim, Myung-Hyun;Kang, Kee-Kyung;Yoon, Seong-Tak
    • Journal of Climate Change Research
    • /
    • v.4 no.4
    • /
    • pp.397-407
    • /
    • 2013
  • Seasons in Korea have very distinguishable features. Due to continental high pressure, spring in Korea is dry and has low precipitation. Due to climate change derived from the increase of greenhouse gases, climate variability had increased and it became harder to predict. This caused the spring drought harsher than usual. Since 1990s, numbers of chronic drought from winter to spring increased in southern regions of Korea. Such drought in the spring damages the growth and development of the crops sown in the spring and decreases its quantity. For stable agricultural production in the future, it is necessary to assess vulnerability of the relationship between spring drought and agricultural production as well as to establish appropriate measures accordingly. This research used CCGIS program to perform vulnerability assessment on spring drought based on climate change scenario SRES A1B, A1FI, A1T, A2, B1, B2 and RCP 8.5 in 232 regions in Korea. As a result, Every scenario showed that vulnerability of spring drought decreased from 2000s to 2050s. Ratio of decrease was 37% under SRES scenario but, 3% under RCP 8.5 scenario. Also, for 2050 prediction, every scenario predicted the highest vulnerability in Chungcheongnam-do. However, RCP-8.5 predicted higher vulnerability in Gyeonggi-do than SRES scenario. The reason for overall decrease in vulnerability of agriculture for future spring drought is because the increase of precipitation was predicted. The assessment of vulnerability by different regions showed that choosing suitable scenario is very important factor.

Packaging Technology for the Optical Fiber Bragg Grating Multiplexed Sensors (광섬유 브래그 격자 다중화 센서 패키징 기술에 관한 연구)

  • Lee, Sang Mae
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.24 no.4
    • /
    • pp.23-29
    • /
    • 2017
  • The packaged optical fiber Bragg grating sensors which were networked by multiplexing the Bragg grating sensors with WDM technology were investigated in application for the structural health monitoring of the marine trestle structure transporting the ship. The optical fiber Bragg grating sensor was packaged in a cylindrical shape made of aluminum tubes. Furthermore, after the packaged optical fiber sensor was inserted in polymeric tube, the epoxy was filled inside the tube so that the sensor has resistance and durability against sea water. The packaged optical fiber sensor component was investigated under 0.2 MPa of hydraulic pressure and was found to be robust. The number and location of Bragg gratings attached at the trestle were determined where the trestle was subject to high displacement obtained by the finite element simulation. Strain of the part in the trestle being subjected to the maximum load was analyzed to be ${\sim}1000{\mu}{\varepsilon}$ and thus shift in Bragg wavelength of the sensor caused by the maximum load of the trestle was found to be ~1,200 pm. According to results of the finite element analysis, the Bragg wavelength spacings of the sensors were determined to have 3~5 nm without overlapping of grating wavelengths between sensors when the trestle was under loads and thus 50 of the grating sensors with each module consisting of 5 sensors could be networked within 150 nm optical window at 1550 nm wavelength of the Bragg wavelength interrogator. Shifts in Bragg wavelength of the 5 packaged optical fiber sensors attached at the mock trestle unit were well interrogated by the grating interrogator which used the optical fiber loop mirror, and the maximum strain rate was measured to be about $235.650{\mu}{\varepsilon}$. The modelling result of the sensor packaging and networking was in good agreements with experimental result each other.

Comparison of the Medication Effects between Milnacipran and Pregabalin in Fibromyalgia Syndrome Using a Functional MRI: a Follow-up Study (섬유근통 환자에 대한 Milnacipran과 Pregabalin 약물치료에 대한 기능적 자기공명영상에서의 후속 영향 비교)

  • Kang, Min Jae;Mun, Chi-Woong;Lee, Young Ho;Kim, Seong-Ho
    • Investigative Magnetic Resonance Imaging
    • /
    • v.18 no.4
    • /
    • pp.341-351
    • /
    • 2014
  • Purpose : In this study, the medication effects of Milnacipran and Pregabalin, as well known as fibromyalgia treatment medicine, in fibromyalgia syndrome patients were compared through the change of BOLD signal in pain related functional MRI. Materials and Methods: Twenty fibromyalgia syndrome patients were enrolled in this study and they were separated into two groups according to the treatment medicine: 10 Milnacipran (MLN) treatment group and 7 Pregabalin (PGB) treatment group. For accurate diagnosis, all patients underwent several clinical tests. Pre-treated and post-treated fMRI image with block-designed pressure-pain stimulation for each group were obtained to conduct the statistical analysis of paired t-test and two sample t-test. All statistical significant level was less than 0.05. Results: In clinical tests, the clinical scores of the two groups were not significantly different at pre-treatment stage. But, PGB treatment group had lower Widespread Pain Index (WPI) and Brief Fatigue Inventory (BFI) score than those of MLN treatment group at post-treatment stage. In functional image analysis, BOLD signal of PGB treatment group was higher BOLD signal at several regions including anterior cingulate and insula than MLN treatment group at post-treatment stage. Also, paired t-test values of the BOLD signal in MLN group decreased in several regions including insula and thalamus as known as 'pain network'. In contrast, size and number of regions in which the BOLD signal decreased in PGB treatment group were smaller than those of MLN treatment group. Conclusion: This study showed that MLN group and PGB group have different medication effects. It is not surprising that MLN and PGB have not the same therapeutic effects since these two drugs have different medicinal mechanisms such as antidepressants and anti-seizure medication, respectively, and different detailed target of fibromyalgia syndrome treatment. Therefore, it is difficult to say which medicine will work better in this study.

Examination of the Current Situations of Security Dogs and it's Development Plans (경호탐지견의 운용실태 및 발전방안)

  • Park, Hyung-Kyu;Kim, Doo-Hyun
    • Korean Security Journal
    • /
    • no.14
    • /
    • pp.215-234
    • /
    • 2007
  • Our country security industry 1960's service expense of the beginning U.S. army unit it accomplishes the growth which is quick with start, currently about 2,500 triumph the security enterprises which it goes over are being active. But the majority in these enterprise about lower cotton can a forever characteristic with pressure and the manpower civil official ability insufficient back of faithlessness management and capital power. To sleep with afterwords it presents the security dogs deployment plan for an efficient security together from the research which it sees hereupon and it does. First, it cultivates the domestic mountain progress dog which is a breed which is suitable with the security dogs and the shovel flesh dog back with the security dogs. Specially the Jindo of the breed which is excellent training which is suitable in task of the security dogs it leads and if it uses appropriately, it industrializes our specific the Jindo and protection there is a possibility of getting the effect which falls to also the gist which it rears rightly. It cultivate the second, security dogs and it magnifies training. The security dogs consequently is it will be able to accomplish the task above 2 branches to training method. Namely, after finishing obedience training, it is to be in security activity it will execute guard or detection back special training which is suitable in task and it will be able to commit. Third, it uses the security dogs which is trained rightly in task. The security dogs the adult escorts, facility expense, the explosive and narcotic drug detection, it will be able to use with the other blind man guidance dogs back. The narcotic drug detection dogs which currently is used specially technique intelligence anger, when considering the tendency of the narcotic drug smuggling offense field which becomes diversification that the role very it is important is a possibility of saying at day. It cultivate a fourth, escort relation specialty manpower and it improves the breed of the security dogs. The hazard which cultivate the security dogs use necessary personnel the breed of security dogs, the security dogs training center it opens the security crane relation subject of the college which stands and (university) it improves it establishes and training which is suitable in task it is to do to execute letting in the training map company. Specially, the hazard which improves the breed of security dogs in the progress mind quality which stands against the portion where the breed improvement is demanded as the portion where the internal organs research and investment are necessary sees. The security dogs compares in labor cost and the expense holds few, if it uses the our specific domestic dogs it will be able to use efficiently in the task which is various it solves the multi branch plans for wisly with the security dogs industrial development security of course contemporary history sliced raw fish sees demands compared to being immediacy and the life which is happy business the place where it does it sees it will be able to contribute a lot as.

  • PDF

Application of Machine Learning Algorithm and Remote-sensed Data to Estimate Forest Gross Primary Production at Multi-sites Level (산림 총일차생산량 예측의 공간적 확장을 위한 인공위성 자료와 기계학습 알고리즘의 활용)

  • Lee, Bora;Kim, Eunsook;Lim, Jong-Hwan;Kang, Minseok;Kim, Joon
    • Korean Journal of Remote Sensing
    • /
    • v.35 no.6_2
    • /
    • pp.1117-1132
    • /
    • 2019
  • Forest covers 30% of the Earth's land area and plays an important role in global carbon flux through its ability to store much greater amounts of carbon than other terrestrial ecosystems. The Gross Primary Production (GPP) represents the productivity of forest ecosystems according to climate change and its effect on the phenology, health, and carbon cycle. In this study, we estimated the daily GPP for a forest ecosystem using remote-sensed data from Moderate Resolution Imaging Spectroradiometer (MODIS) and machine learning algorithms Support Vector Machine (SVM). MODIS products were employed to train the SVM model from 75% to 80% data of the total study period and validated using eddy covariance measurement (EC) data at the six flux tower sites. We also compare the GPP derived from EC and MODIS (MYD17). The MODIS products made use of two data sets: one for Processed MODIS that included calculated by combined products (e.g., Vapor Pressure Deficit), another one for Unprocessed MODIS that used MODIS products without any combined calculation. Statistical analyses, including Pearson correlation coefficient (R), mean squared error (MSE), and root mean square error (RMSE) were used to evaluate the outcomes of the model. In general, the SVM model trained by the Unprocessed MODIS (R = 0.77 - 0.94, p < 0.001) derived from the multi-sites outperformed those trained at a single-site (R = 0.75 - 0.95, p < 0.001). These results show better performance trained by the data including various events and suggest the possibility of using remote-sensed data without complex processes to estimate GPP such as non-stationary ecological processes.

Effects of Silkworm Powder on Blood Glucose and Lipid Levels in NIDDM(Type II) Patients (인슐린 비의존형(Type II) 당뇨환자에서 누에분말 섭취가 혈당 및 혈중지질농도에 미치는 영향)

  • 조미란;조여원;정성현;류재환
    • Journal of Nutrition and Health
    • /
    • v.31 no.7
    • /
    • pp.1139-1150
    • /
    • 1998
  • The purpose of this study is to investigate the effects of the silkworm powder on blood levels of glucose, Hb Alc, insulin, and lipids. Thirty-one NIDDM patients from Kyung Hee Medical Center were divided into two groups : patients with silkworm powder supplements and drug treatments(Drug diabetes) and patients with silkworm powder supplement only(Non-drug diabetes). For the control group, age-matched subjects were recruited. During the 4 weeks of the experimental period, silkworm powder(500mg/mea1) was given to the subjects right after each meal. Nutritional assessments and dietary education were carried out periodically, and body weight and blood pressure were measured when patients visited the hospital. Overnight fasting and 2-h postprandial blood glucose levels were measured at 2 week intervals. The blood levels of insulin, Hb Alc, and lipids were measured before and after the supplements. The mean ages of the three groups were 56.7-59.6 years old. The height, weight, and BMI did not differ among the groups. The fasting blood glucose levels were 138.1$\pm$22.0mg/dl for the Drug treated diabetes group, 175.0$\pm$32.0mg/dl for the Non-drug diabetes group, and 108. 3$\pm$16.gmg/dl for the control group at the begining of the supplement. After 4-wks of supplements, the blood levels of glucose tended to decrease in all three experimental groups. Before the supplements, the 2-h postprandial blood glucose levels of the Drug diabetes, Non drug diabetes, and control groups were 244.7$\pm$62.6mg/dl, 272.4$\pm$40.1mg/dl, and 147.7$\pm$28.0mg/dl, respectively. After the supplement, the levels were 197.2$\pm$30.gmg/dl, 208.6$\pm$ 56.6mg/dl, and 151.3$\pm$30.3mg/dl, respectively. This shows that silkworm powder tended to lower blood levels by 19.4% and 23.4% in NIDDM patient groups. However, the changes in the blood levels of insulin, Hb Alc, ind lipids were not observed after the supplement. In conclusion, the present study has demonstrated that silkworm powder has a tendency to decrease 2-h postprandial blood glucose levels, but it should be used with caution in controlling the diabetes. (Korean J Nutrition 31(7) 1139-1150, 1998)

  • PDF

Blockade of Thromboxane Influences Does Not Affect Renal Blood Flow Deficit in Anesthetized Diabetic Rats (마취된 당뇨 흰쥐의 신혈류량 감소에 관여하는 기전 : 내인성 쓰롬복산계의 무관성)

  • Ha, Hun-Joo;Dunham, Earl W.
    • The Korean Journal of Pharmacology
    • /
    • v.24 no.2
    • /
    • pp.221-232
    • /
    • 1988
  • Studies were conducted to determine whether reduced renal blood flow (RBF) exhibited by rats with uncontrolled, streptozotocin (STZ)-induced diabetes is attributable to diabetes-associated, enhanced renal vasoconstrictor influence of endogenous thromboxane $(TX)A_2$. Rats which were injected with STZ after pretreatment with 3-O-methyl glucose (3OMG), an agent which prevents STZ-induced hyperglycemia, were also studied. Basal values of total RBF (RBF; ml $min^{-1}$ $gKw^{-1}$; electromagnetic flow probe), systemic arterial pressure (BP; mm Hg) and renal vascular resistance (RVR;BP $RBF^{-1})$in pentobarbital-anesthetized rats during a control period were $5.9{\pm}0.3$(P<0.1_{VS}. CR), $115{\pm}3$ and $20.3{\pm}1.0$(P<0.1_{VS}. CR) for STZR (n=15), and $8.4{\pm}0.4$, $123{\pm}3$ and $15.1{\pm}0.8$ for age-matched control rats (CR; n= 15), respectively. Basal values of RBF, BP and RVR in 3OMG pretreated STZR were identical to CR. In preparations shown capable of renal vasodilatation, OKY 1581 (1 mg/kg, i.v. followed by 0.4 mg/kg min infusion) abolished arachidonate-induced $(TX)A_2$ synthesis, but did not alter basal BP, RBF or RVR in either STZR or CR (n=4/group). Similarly, i.r.a. infusion of SQ29548 (100 ng/ml RBF) abolished renal vasoconstriction induced by a TX/prostaglandin endoperoxide mimic, U46619, but had no discern able affect on RVR in either STZR (n=8) or CR (n=8). The data indicates that $TXA_2$ does not participate in the elevated basal RVR of STZR which are associated with the diabetic state.

  • PDF

Relation Between Obesity Indices and, Nutritional Knowledge Nutritional Status and Blood Parameters in Obese Middle-School Students (비만 중학생의 비만도와 영양지식, 영양섭취상태 및 혈액성상과의 상관성)

  • Choi, Mi-Kyeong;Kim, Mi-Hyun;Lee, Yoon-Shin;Cho, Hye-Kyung;Kim, Kyeong-Hi;Lee, Bo-Bae;Sung, Mi-Kyung;Sung, Chung-Ja
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.34 no.2
    • /
    • pp.181-189
    • /
    • 2005
  • The purpose of this study was to investigate the relationship between obesity indices, nutritional knowledge, nutritional intake status, and some blood parameters in obese middle-school students. Anthropometric measurement, 24-hour recall for dietary intake, blood analysis and Questionnaire response including nutritional knowledge, nutritional attitude, and self-satisfaction were conducted in 42 obese middle-school students (28 male and 14 female) participated in the nutritional camp program carried by Bucheon district public health center in Kyunggi-do. The mean age of subjects was 13.9 years. The average body weight, BMI, obesity index, WHR and percent body fat were 75.5 kg, 29.1 kg/$m^2$, 30.1, 0.89 and 33.3% in male subjects, and 67.8 kg, 27.5 kg/$m^2$, 25.3, 0.81 and 34.6% in female subjects. The average nutritional attitude, the self-satisfaction and the nutritional knowledge scores were no significant difference between male and female subjects. Average intake of energy were 85.5% of RDA in males and 98.1% of RDA in females. The percentage of energy from fat was higher in both male (29%) and female (26%) subjects than recommended level. Calcium, iron, zinc, vitamin A, vitamin B$_2$, vitamin C, niacin and folate intakes were below the RDA for them. In the results of correlation analysis, body weight, BMI and obesity index were positively correlated with systolic blood pressure and cholesterol intake. There was a negative correlation between percent body fat and nutritional knowledge. Body weight was negatively related to HDL-cholesterol, whereas it has positive relation with RBC, hemoglobin and hematocrit. BMI and obesity index were negatively related to HDL-cholesterol, but positively related to RBC, respectively. WHR showed positive relationship with serum GPT, glucose and MCV.

Evaluation of cardiac function by tissue Doppler imaging in children with cancer (Tissue Doppler imaging을 이용한 소아 종양 환자에서의 심기능 평가)

  • Kim, Yeo Hyang
    • Clinical and Experimental Pediatrics
    • /
    • v.49 no.4
    • /
    • pp.417-423
    • /
    • 2006
  • Purpose : The objectives of this study were to assess ventricular function by tissue Doppler imaging in children who were receiving chemotherapy or who had received chemotherapy, and to apply repeated tissue Doppler imaging to make an early assessment in cardiac toxicity studies. Methods : This study was conducted on 23 oncology patients on-treatment or off-treatment from April 2005 to July 2005 at Dongsan Medical Center, Keimyung University. All patients(group 1) were divided into two groups, fractional shortening(FS) over 29 percent(group 2) and FS under 28 percent (group 3) in the first category. These same patients were also divided into the following groups : group treated with anthracyclin(group 4) and group treated without anthracyclin(group 5). Deceleration time(DT), isovolumic relaxation time(IVRT), FS, peak early diastolic(E), and peak late diastolic (A) velocity of transmitral flow were measured by M-mode and pulsed wave Doppler. Systolic(Sm), peak early diastolic(Em), and peak late diastolic(Am) velocity in apical 4-chamber and 2-chamber views were measured by tissue Doppler imaging. The author calculated a modified Tei index, E/A, E/Em ratio by using measured values. Results : Twenty three patients were enrolled : 12 boys and 11 girls. The average age of patients was 8 years and 4 months. Thirteen out of 23 patients were in the group treated with anthracyclin (group 4) and 6 had FS under 28 percent(group 3). E/Em ratio showed a significant difference between group 1 and control group($6.46{\pm}1.85$ vs $7.06{\pm}1.64$, P<0.05). Other parameters had no difference statistically. Conclusion : This study showed that the change of cardiac function developed earlier in diastolic function than in systolic function, as E/Em ratio reflecting the mean LV diastolic pressure showed a significant difference between the control group and chemotherapy groups. Echocardiography using tissue Doppler imaging is a non-invasive, comfortable and reliable method for post-chemotherapy follow up.