• Title/Summary/Keyword: 하한값

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Study on Comparison of Methods for Estimation of Shear Wave Velocity in Core Zone of Existing Dam (기존 댐 코어죤의 전단파속도 산정기법 비교 연구)

  • Ha, Ik-Soo;Oh, Byung-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.24 no.10
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    • pp.33-43
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    • 2008
  • In this study, for the purpose of evaluating the shear wave velocity in core zone, cross-hole test, down-hole test, MASW (Multi-channel Analysis of Surface Wave), and seismic reflection survey were carried out on the crest of the existing 'Y' dam. The results of field tests were compared one another. Furthermore, the field test results were compared with the result by the Sawada's empirical recommendation method. The purpose of this study is to compare the results of four kinds of field tests for evaluation of shear wave velocity in core zone of existing dam, to verify applicability of the empirical method which was recommended by Sawada and Takahashi, and to recommend a reasonable method for evaluation of shear wave velocity which is needed to evaluate tile maximum shear modulus of core zone. From the results of four kinds of field tests such as cross-hole test, down-hole test, MASW, and seismic reflection survey, it was found that the shear wave velocity distributions were similar within 18 m in depth and the results obtained by MASW and seismic reflection survey were almost the same by 30 m in depth. For evaluation of shear wave velocity in core zone of the existing dam, in consideration that it is not easy to bore the hole ill the core zone of existing dam, surface surveys such as MASW and seismic reflection method are recommended as realistic methods. On condition that it is impossible to conduct the field test and it is preliminary investigation, it is recommended that Sawada's low bound empirical equation be used.

Estimation of Friction Coefficients Based on Field Data (실측값에 근거한 마찰계수의 추정)

  • Jeon, Se Jin;Park, Jong Chil;Park, In Kyo;Shim, Byul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.487-494
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    • 2009
  • Friction coefficients of the prestressing tendon are the basic information required to control the prestressing force introduced to PSC structure during jacking. However, the friction coefficients show considerable differences depending on the specifications, causing much confusion to designers. In this study, the ranges of the friction coefficients presented in domestic and foreign specifications are compared together to clarify the differences. Then, a procedure is proposed that can be used to estimate the wobble and curvature friction coefficients from field data such as elongation and prestressing force and from theory related to the friction. The procedure is applied to various tendon profiles of several PSC bridges constructed by ILM, FCM and MSS. The resulting values are compared with those presented in some specifications and assumed in jacking and a reasonable range of the friction coefficient is discussed. Lift-off tests are also performed in some bridges to further verify the results. The resulting wobble friction coefficients are not as small as those presented in AASHTO specifications but range from the lower limit to mid point of domestic specifications, while the curvature friction coefficients approach or slightly exceed the upper limit.

Effectiveness of Real-time Oxygen Control in Fresh Produce Container Equipped with Gas-diffusion Tube (기체확산 튜브 부착 신선 농산물 용기에서의 실시간 산소농도 제어의 효과)

  • Jo, Yun Hee;An, Duck Soon;Lee, Dong Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.19 no.3
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    • pp.119-123
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    • 2013
  • Simplified control logic was devised to fabricate and operate the modified atmosphere (MA) container of fresh produce equipped with gas-diffusion tube whose opening/closing was controlled in response to real time $O_2$ concentration. This is a simplified ramification of the previously developed control logic using both $O_2$ and $CO_2$ concentrations ([$O_2$] & [$CO_2$]). The developed logic was applied to and tested by a container system filled with spinach at $10^{\circ}C$ having optimum MA window of [$O_2$] of 7~10% and [$CO_2$] of 5~10%. It was shown that setting the proper on-off limit (11%) for $O_2$ control based on the assumed relationship $[O_2]+[CO_2]$=21% could attain the desired $CO_2$ concentration just below the upper tolerance limit ($[CO_2]_H$, 10%). The $O_2$ control point can be the lower tolerance limit or adjusted one (21-$[CO_2]_H$) depending on the commodity's MA requirement. The developed logic using single $O_2$ sensor could attain the equilibrated [$O_2$] of 11% with [$CO_2$] of 8~9% which was desired and similar to that of its predecessor ([$O_2$] of 9~10% with [$CO_2$] of 10%) using both $O_2$ and $CO_2$ sensors. Both MA containers (one only with single $O_2$ sensor control and one with $O_2$ and $CO_2$ sensors) could also keep the spinach quality without significant difference between them, but significantly better than perforated control package of air.

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Antibody Responses in Hematopoietic Cell Transplantation Recipients after Vaccination Against Haemophilus Influenzae Type b and Streptococcus pneumoniae (소아 조혈모세포 이식 환자에서 b형 헤모필루스 인플루엔자와 폐렴구균 백신 접종 후 항체 반응에 관한 연구)

  • Kim, Yae-Jean;Hwang, Ji-Young;Choi, Soo-Han;Kong, Eunhye;Kim, Yanghyun;Park, Ki-Sup;Yoo, Keon-Hee;Sung, Ki-Woong;Koo, Hong Hoe;Kim, Kyung-Hyo
    • Pediatric Infection and Vaccine
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    • v.21 no.2
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    • pp.81-95
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    • 2014
  • Purpose: Hematopoietic cell transplantation (HCT) recipients are vulnerable to invasive infection by Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (Sp). This study was performed to evaluate immune responses after Hib and Sp vaccination in Korean pediatric HCT recipients. Methods: Patients were prospectively enrolled at Samsung Medical Center during 2009-2011. ELISA tests to detect anti-PRP IgG antibody and antibodies to Sp serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F were performed at the Center for Vaccine Evaluation and Study, Ewha Medical Research Institute. Results: Ten patients (two allogeneic, eight autologous recipients) with median age 5.4 years (range 2.7-12.2 years) were enrolled. Before Hib vaccination, 60% of patients' anti-PRP IgG titers were below $0.15{\mu}g/mL$. After vaccination, 100% of patients' anti-PRP IgG titers increased above $0.15{\mu}g/mL$ (cut-off value for detection) and $1.0{\mu}g/mL$ (cut-off value for seroprotection). For pneumococcus, in 2-5 year-old patients, pre-vaccination geometric mean concentrations (GMCs) of IgG for six serotypes (4, 6B, 9V, 14, 18C, and 23F) were below $0.35{\mu}g/mL$ and at 5 months post-vaccination GMCs of IgG for all seven serotypes increased to above $0.35{\mu}g/mL$. In patients older than 5 years, pre-vaccination GMCs of IgG for four serotypes (4, 9V, 14, and 23F) were below $0.35{\mu}g/mL$ and at 3 months post-vaccination GMCs of IgG for all seven serotypes increased to above $0.35{\mu}g/mL$. Conclusion: Most HCT recipients had low or no protective antibodies to Hib and Sp before vaccination, but showed good immune responses to protective levels after vaccination.

Temperature Data-Based Assessment of the Marginal Heading Dates and the Growth Duration of Rice in the Regions of North Korea (북한 지역의 기온 자료를 활용한 벼 출수 한계기 및 재배 기간 분석)

  • Yang, Woonho;Kang, Shingu;Kim, Sukjin;Choi, Jong-Seo;Park, Jeong-Hwa
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.4
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    • pp.284-295
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    • 2018
  • The safe and late marginal heading dates (SMHD, LMHD), cropping probability, and growth duration of rice were assessed using temperature data in the 27 regions of North Korea. The medians of SMHD and LMHD ranged Jul. 16 and Jul. 27 in Hyesan to Aug. 18 and Aug. 28 in Haeju, respectively, except Changjin, Pungsan, and Samjiyon that did not show any of the SMHD and LMHD. The medians of the days from early marginal transplanting date (EMTD) to heading date ranged 51 days in Hyesan to 109 days in Pyongyang for SMHD and those were delayed by 9~15 days for LMHD, compared to SMHD. Nineteen regions (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, Pyongyang, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Yangdok, Huichon, Supung, Sinpo, Kanggye) and additional four regions (Kimchaek, Chongjin, Sonbong, Chunggang) had the rice cropping probability higher than 80% when analyzed based on the SMHD and LMHD, respectively. The representative SMHD ranged Jul. 24 for Pyonggang to Aug. 12 for Haeju. Compared to the days from EMTD to SMHD, those from EMTD to LMHD were delayed by 9~17 days. When applied SMHD, thirteen regions (Yangdok, Kanggye, Huichon, Supung, Yongyon, Kusong, Anju, Sinuiju, Singye, Pyongyang, Kaesong, Nampo, Sariwon) had the appropriate range of cumulative temperature during grain filling (CT) for grain yield and quality. Sinpo, Hamhung, Pyonggang, Wonsan, Changjon, and Haeju had the CT higher than $1,300^{\circ}C$. It is supposed that rice cropping could be extended to the regions where LMHD-applied cropping probability was higher than 80%. Delaying the heading date than SMHD could be also considered in the regions where the days to SMHD is small but CT is large.

The Role of Tumor Necrosis Factor-$\alpha$ and Interleukin-$1{\beta}$ as Predictable Markers for Development of Adult Respiratory Distress Syndrome in Septic Syndrome (패혈증 증후군환자에서 성인성 호흡곤란 증후군 발생의 예측 지표서의 혈중 Tumor Necrosis Factor-$\alpha$와 Interleukin-$1{\beta}$에 관한 연구)

  • Koh, Youn-Suck;Jang, Yun-Hae;Kim, Woo-Sung;Lee, Jae-Dam;Oh, Soon-Hwan;Kim, Won-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.5
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    • pp.452-461
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    • 1994
  • Background: Tumor necrosis factor(TNF)-$\alpha$ and Interleukin(lL)-$1{\beta}$ are thought to play a major role in the pathogenesis of the septic syndrome, which is frequently associated with adult respiratory distress syndrome(ARDS). In spite of many reports for the role of TNF-$\alpha$ in the pathogenesis of ARDS, including human studies, it has been reported that TNF-$\alpha$ is not sensitive and specific marker for impending ARDS. But there is a possibility that the results were affected by the diversity of pathogenetic mechanisms leading to the ARDS because of various underlying disorders of the study group in the previous reports. The purpose of the present study was to evaluate the roles of TNF-$\alpha$ and IL-$1{\beta}$ as a predictable marker for development of ARDS in the patients with septic syndrome, in which the pathogenesis is believed to be mainly cytokine-mediated. Methods: Thirty-six patients of the septic syndrome hospitalized in the intensive care units of the Asan Medical Center were studied. Sixteens suffered from ARDS, whereas the remaining 20 were at the risk of developing ARDS(acute hypoxemic respiratory failure, AHRF). In all patients venous blood samples were collected in heparin-coated tubes at the time of enrollment, at 24 and 72 h thereafter. TNF-$\alpha$ and IL-$1{\beta}$ was measured by an enzyme-linked immunosorbent assay (ELISA). All data are expressed as median with interquartile range. Results: 1) Plama TNF-$\alpha$ levels: Plasma TNF-$\beta$ levels were less than 10pg/mL, which is lowest detection value of the kit used in this study within the range of the $mean{\pm}2SD$, in all of the normal controls, 8 of 16 subjects of ARDS and in 8 in 20 subjects of AHRF. Plasma TNF-$\alpha$ levels from patients with ARDS were 10.26pg/mL(median; <10-16.99pg/mL, interquartile range) and not different from those of patients at AHRF(10.82, <10-20.38pg/mL). There was also no significant difference between pre-ARDS(<10, <10-15.32pg/mL) and ARDS(<10, <10-10.22pg/mL). TNF-$\alpha$ levels were significantly greater in the patients with shock than the patients without shock(12.53pg/mL vs. <10pg/mL) (p<0.01). There was no statistical significance between survivors(<10, <10-12.92pg/mL) and nonsurvivors(11.80, <10-20.8pg/mL) (P=0.28) in the plasma TNF-$\alpha$ levels. 2) Plasma IL-$1{\beta}$ levels: Plasma IL-$1{\beta}$ levels were less than 0.3ng/mL, which is the lowest detection value of the kit used in this study, in one of each patients group. There was no significant difference in IL-$1{\beta}$ levels of the ARDS(2.22, 1.37-8.01ng/mL) and of the AHRF(2.13, 0.83-5.29ng/mL). There was also no significant difference between pre-ARDS(2.53, <0.3-8.34ngfmL) and ARDS(5.35, 0.66-11.51ng/mL), and between patients with septic shock and patients without shock (2.51, 1.28-8.34 vs 1.46, 0.15-2.13ng/mL). Plasma IL-$1{\beta}$ levels were significantly different between survivors(1.37, 0.4-2.36ng/mL) and nonsurvivors(2.84, 1.46-8.34ng/mL). Conclusion: Plasma TNF-$\alpha$ and IL-$1{\beta}$ level are not a predictable marker for development of ARDS. But TNF-$\alpha$ is a marker for shock in septic syndrome. These result could not exclude a possibility of pathophysiologic roles of TNF-$\alpha$ and IL-$1{\beta}$ in acute lung injury because these cytokine could be locally produced and exert its effects within the lungs.

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