• Title/Summary/Keyword: Local mean age

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A Study for Optimization the Ventilation Performance of the Computer Room (전산실의 환기성능 최적화를 위한 연구)

  • Kwon, Yong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.2
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    • pp.57-62
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    • 2015
  • The objective of the present study is to identify the ventilation problems and to suggest the optimal ventilation system to save energy and to improve IAQ in the computer rooms, which annually performs the cooling operation by the server with the highly thermal load. Numerical results on the temperature and local mean age are presented along with some of the discharge velocities. Results show many interesting aspects of airflow patterns affecting the ventilation performances, according to the discharge velocity of the supply diffuser installed in the bottom surfaces between the servers. As the results, 2.5 m/s of the optimal discharge velocity is needed in order to improve the ventilation performance.

Determinate the Number of Growth Rings Using Resistograph with Tree-Ring Chronology to Investigate Ages of Big Old Trees

  • OH, Jung-Ae;SEO, Jeong-Wook;KIM, Byung-Ro
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.6
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    • pp.700-708
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    • 2019
  • To verify the possibility of using resistograph to estimate the age of big old living trees, we selected three Zelkova serrata and seven Pinus densiflora in Goesan. The mean diameters at breast height of Z. serrata and P. densiflora were 102 (92-116) cm and 80 (65-110) cm, respectively. The heights measured from the ground using a resistograph ranged at 1.2-4.3 m and 0.6-1.1 m for Z. serrata and P. Densiflora, respectively. The most appropriate needle speed to determine tree-ring boundaries for measuring ring width was 1500 r/min for both tree species. Alternatively, the suitable feed speeds for Z. serrata and P. densiflora were 50 cm/min and 150 cm/min, respectively. From the measured data, the mean numbers of tree rings of Z. serrata and P. densiflora were 57 (43-68) and 104 (93-124), respectively, and the mean tree-ring widths were 4.27 mm (3.18-5.09 mm) and 2.93 mm (2.32-3.34 mm), respectively. A comparison between the time series of tree-ring widths by resistograph and that from the local master chronologies tallied for the heartwood part. Finally, this study showed that resistograph can be used to estimate tree ages when a local master chronology is available.

A Study to Evaluate the Efficacy of 9.6% Lidocaine of Local Anesthesia for Pain Reduction of Venipuncture in the ED (응급실에서 정맥주사 시행 시 9.6% 리도카인 표면국소마취제의 진통효과)

  • Park, Duk;Ryu, Ji Yeong;Cho, Gyu Chong;You, Ji Young
    • Journal of Trauma and Injury
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    • v.20 no.2
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    • pp.115-118
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    • 2007
  • Purpose: A eutectic mixture of local anesthetics (EMLA$^{(R)}$) cream has been used as a topical anesthetic to reduce the pain of procedures penetrating the skin. It is generally applied for 40 to 60 minutes before the painful procedure. Because of the long application period, EMLA$^{(R)}$ is not useful in the emergency department (ED). The purpose of this study was to determine whether a 20-minute application of 9.6% lidocaine would be useful in reducing the pain of routine peripheral intravenous cannulation in the ED. Methods: We examined 27 male and 19 female patients ages over 18 years of age who required intravenous cannula insertion. Intravenous insertion was performed on 46 patients: 24 patients in the placebo group (mean age: 40.0 years) and 22 in the 9.6% lidocaine group (mean age: 37.6 years). The 9.6% lidocaine or placebo gel was applied and covered with an occlusive dressing for 20 minutes. Pain was scored by the patients using a 0- to 10-cm visual analogue scale. Results: The patients in the 9.6% lidocaine group (mean pain score: 3.4) experienced less pain than those in the placebo group (mean: 5.3), and the difference was statistically significant (p=0.029). Conclusion: We concluded that a 20-minute application of 9.6% lidocaine is safe and effective for reducing pain associated with venipuncture.

Measurements of Ventilation Effectiveness in an Underfloor Air-Conditioned Space Using a Tracer Gas Technique

  • Han, Hwa-Taik;Seo, S.Y.;Kim, M.H.;Kim, Young-Il
    • International Journal of Air-Conditioning and Refrigeration
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    • v.7
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    • pp.91-100
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    • 1999
  • This paper investigates ventilation characteristics of an environmental chamber simulating an under-floor air conditioning system for isothermal and cooling supply air conditions. The tracer gas sulfur-hexafluoride (SF$F_6$) was injected into a supply duct using step-up and step-down methods. Local mean and room mean ages were calculated from the concentrations measured at internal points and at the exhaust duct. The air change efficiency of the chamber has been found to be greater in cooling conditions than in isothermal conditions. Also the room air change efficiency is not significantly affected but slightly improved by the presence of a supply diffuser.

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Ventilation effectiveness measurements utilizing a tracer gas in an under floor air-conditioning space (추적가스를 이용한 바닥취출 공조공간내의 환기효율 측정실험)

  • 한화택;서세영;김명호;김영일
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.5
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    • pp.610-618
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    • 1998
  • In this study, a tracer gas technique was used to measure ventilation effectiveness in a thermal environmental chamber simulating an under-floor air conditioning system. A tracer gas of $SF_6$ was injected in a supply duct using step-up and step-down methods. Local mean ages and room mean ages were calculated from the measured concentrations under isothermal and cooling conditions with and without diffusers. Ventilation effectiveness is found to be higher in cooling ventilation operations than in isothermal operations. Results also show that ventilation effectiveness is not significantly affected by a diffuser.

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Yonsei Evolutionary Population Synthesis for Old Stellar Systems

  • Chung, Chul
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.31.2-31.2
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    • 2012
  • We present the Yonsei Evolutionary Population Synthesis (YEPS) models for spectroscopic and photometric evolutions of simple and composite stellar populations. The models are based on the most up-to-date Yonsei-Yale stellar evolutionary tracks and BaSel 3.1 flux libraries, and provide integrated spectroscopic quantities of Lick/IDS system including high-order Balmer absorption-lines. Special care has been taken to incorporate the systematic variation of horizontal branch (HB) morphology as functions of metallicity, age, alpha-element mixture, and helium abundance of simple stellar populations. Our models for normal-helium stellar populations indicate that the realistic modeling of HB and alpha-element brings about 5 Gyr and 0.1 dex differences in age and metallicity estimations, respectively, compared to those without these effects. The HB effect does not depend on the specific choice of stellar libraries and alpha-element enhancements, and this effect is non-negligible even in the metal sensitive absorption indices, such as Mg2 and Mg b. Comparison of the models to observations reveals that the HB and alpha-element effects are critical in understanding otherwise inexplicable phenomena found in globular cluster systems in the Milky Way and nearby galaxies, including the observed bimodality of the line strengths of globular clusters in massive galaxies. In addition, we found that helium-enhanced stellar populations, which are the major sources of extreme HB stars, bring about increased FUV, NUV fluxes, and thus the model colors of those filters become extremely blue. Age dating based on the YEPS model with normal-helium stellar populations reveals that the evidence for 'downsizing' of elliptical galaxies is found not only in the local field but also in Coma cluster, and that the mean age of elliptical galaxies in Coma cluster is about 1.4 Gyr younger than the mean age of those in the local field. We also find that our models with helium-enhanced subpopulations can naturally reproduce the strong UV-upturns observed in giant elliptical galaxies assuming an age similar to that of old GCs in the Milky Way.

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Surgical Treatment of Atrioventricular Septal Defect (방실중격결손증의 외과적 치료)

  • 이광숙
    • Journal of Chest Surgery
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    • v.22 no.6
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    • pp.990-995
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    • 1989
  • Since 1984, 24 patients underwent repair of atrioventricular septal defect. Nineteen had a partial defect and 5 had a complete atrioventricular septal defect. There were 9 men and 15 women, ranging in age from 1 to 50 years [mean age, 13.3 years]. Four patients had a Downs syndrome. Additional congenital heart defects were present in 11 patients. One patient had palliative operation prior to total correction. In partial defects, the primum atrial septal defect was closed with Xenomedica patch and the mitral valve was repaired with simple closure of the septal commissure. Central incompetence from annular dilatation was repaired by a local annuloplasty. In complete defect, the septal defects were closed with two patches except one. Operative mortality was 5% in partial defects and 60% in complete defects and low cardiac output was the commonest etiology. In a mean follow-up period of 27.9 months [range, 4 to 63 months] there were no late death and no instances of late-onset complete heart block. One patient required reoperation [MVR] for residual mitral regurgitation. The majority of patients were asymptomatic and mean postop. NYHA functional class was 1.2.

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A Randomized Clinical Trial of Local Acupoints Compared with Distal Acupoints in Degenerative Osteoarthritis on Knee (퇴행성 슬관절염에 대한 근위취혈과 원위취혈 침 치료의 효과 비교에 대한 임상연구)

  • Park, In-Shik;Jung, Chan-Young;Jang, Min-Ki;Kang, Mi-Suk;Lee, Seung-Woo;Kim, Eun-Jung;Lee, Seung-Deok;Kim, Kap-Sung
    • Journal of Acupuncture Research
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    • v.25 no.2
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    • pp.227-242
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    • 2008
  • Objectives : To compare the efficacy of local acupoint with distal acupuncture at relieving pain and improving function in knee osteoarthritis. Designs : A randomized, single-blinded, crossover clinical trial. Settings : One outpatient clinic(department of acupuncture & moxibustion) located in academic teaching hospital, South Korea. Patients : 17 patients with osteoarthritis of the knee(mean age 62.76[$SD{\pm}4.37$] years). Interventions : The trial had 4 stages : baseline(2weeks), phase I and II(each 2weeks), washout period(2weeks). Patients were randomly assigned to either group A or group B. Group A received acupuncture at local acupoints during phase I, then acupuncture at distal acupoints in phase II. Group B received the treatments in reverse order. In each phase, the patients were treated with acupuncture for 6 times. Measurements : The primary outcome was subjective pain as measured by a 100mm visual analogue scale(VAS) ranging from 0(no pain) to 10(worst pain ever). Secondary outcomes were changes in the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC) total and pain scores. Measurements were obtained at baseline, 1st day of phase I and II, and 2 days after last treatment of phase I and II. Results : The 17 participants in 2 groups were well matched for age, sex, target knees, baseline VAS score, WOMAC pain score and WOMAC score. Participants in local acupoint group experienced greater improvement than distal acupoint group at 2 days after last treatment in WOMAC total score(mean difference, -10.65[95% CI, -20.56 to -0.74] ; P=0.036) but not in VAS(mean difference, -12.41[95% CI, -29.56 to 4.73] P=0.15) and WOMAC pain score(mean difference, -1.82[95% CI, -3.98 to 0.33] ; P=0.094). Conclusions : Local acupoints are more effective than distal acupoints at relieving pain and improving function in knee osteoarthritis.

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Constant score in asymptomatic shoulders varies with different demographic populations: derivation of adjusted score equation

  • Nitesh Gahlot;Ankit Rai;Jeshwanth Netaji
    • Clinics in Shoulder and Elbow
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    • v.25 no.4
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    • pp.274-281
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    • 2022
  • Background: In the present study, the age- and sex-adjusted Constant score (CS) in a normal Indian population was calculated and any differences with other population cohorts assessed. Methods: The study participants were patients who visited the outpatient department for problems other than shoulder and healthy volunteers from the local population. Patients without shoulder pain/discomfort during activity were included in the study. Subjects with any problem that might affect shoulder function (e.g., cervical, thoracic spine, rib cage deformity, inflammatory arthritis) were excluded. Constant scoring of all participants was performed by trained senior residents under the supervision of the senior faculty. Shoulder range of movement and strength were measured following recommendations given by the research and Development Committee of the European Society for Shoulder and Elbow Surgery (2008). A fixed spring balance was used for strength measurement; one end was fixed on the floor and the other end tied with a strap to the wrist of the participant, arm in 90° abduction in scapular plane with palm facing down. Results: Among the 248 subjects (496 shoulders), the average age was 37 years (range, 18-78 years), 65.7% were males (326 shoulders) and 34.3% females (170 shoulders). The mean CS was 84.6±2.9 (males, 86.1±3.0; females, 81.8±2.9). CS decreased significantly after 50 years of age in males and 40 years of age in females (p<0.05). The mean CS was lower than in previous studies for both males and females. Heavy occupation workers had higher mean CS (p<0.05). A linear standardized equation was estimated for calculating the adjusted CS for any age. Conclusions: Mean CS and its change with age differed from previous studies among various population cohorts.