• Title/Summary/Keyword: P-delta 영향

Search Result 381, Processing Time 0.028 seconds

A Study on the Analysis of Steel Bracing Behaviour Subjected to Cyclic Loads (반복하중을 받는 강재 브레이싱의 거동에 관한 해석적 연구)

  • 구민세;김병석;김일곤
    • Computational Structural Engineering
    • /
    • v.2 no.3
    • /
    • pp.69-75
    • /
    • 1989
  • The primary purpose of using bracings is to improve the lateral rigidity of main structural system, i.e., columns and beams, by reinforciing them with much smaller members. In conventional design methods brackings are considered as tension-only members, since difficulties arise in the analysis when the P-.DELTA. effects and post-buckling behaviour of the bracing members are taken into account. This is particulary true fox X-bracings. Recently, however, both analytical and experimental studies have been conducted to investigate the more precise and real behaviour of bracing members, especially for the nonlinear and plastic behaviour under cyclic loads. In this study, an analytical model is proposed to investigate the nonlinear behavior of steel bracing members subjected to cyclic loads. Results of the analysis were compared with previous experimental results, and good agreements were obtained between these results.

  • PDF

Fabrication and Modulation Characteristic of TE-selective P-I-i-I-N GaAs/Al0.35Ga0.65As waveguide phase modulator (TE 모드의 위상변화만을 일으키는 P-I-i-I-N GaAs/Al0.35Ga0.65As 도파로 위상변조기의 제작 및 변조 특성)

  • Kim, Sun-Pil;Lee, Sang-Sun;Lee, Seok;Woo, Deok-Ha;Kim, Sun-Ho
    • Korean Journal of Optics and Photonics
    • /
    • v.14 no.2
    • /
    • pp.184-188
    • /
    • 2003
  • We fabricated a P-I-i-I-N $GaAs/Al_{0.35}Ga_{0.65}As$waveguide phase modulator with significant phase shift for the TE mode but negligible for the TM mode. We selected the P-I-i-I-N structure to cause a phase shift about the TM mode. The wavelength of $\lambda=1.55$\mu\textrm{m}$ was measured for both the TE and TM modes, respectively. As a result, the measured phase shift efficiency ($\Delta\phi$) by using the Fabry-Perot resonance method was $7.9^{\circ}/V.mm$ for TE-polarized light. Also, no modulation was observed for TM-polarized light.

Effects of $Bi_2$$O_3$ additions on the dielectric and piezoelectric properties in Pb($Zr_{0.54}$, $Ti_{0.46}$)$O_3$ ($Bi_2$$O_3$첨가량이 Pb($Zr_{0.54}$, $Ti_{0.46}$)$O_3$의 유전, 압전특성에 미치는 영향)

  • 배이열;서동수
    • Electrical & Electronic Materials
    • /
    • v.6 no.3
    • /
    • pp.207-213
    • /
    • 1993
  • Pb(Z $r_{0.54}$, $Ti_{0.46}$) $O_{3}$에 B $i_{2}$ $O_{3}$를 0.0wt%까지 첨가하여 미세구조, 유전, 압전, 성질에 미치는 영향을 고찰하였다. B $i_{2}$ $O_{3}$의 고용범위는 약 0.5~0.7wt%정도 이었고 B $i_{2}$ $O_{3}$ 첨가량이 증가함에 따라서 결정립의 크기가 감소하였다. B $i_{2}$ $O_{3}$첨가량이 증가함에 따라 고용한계까지는 $d_{33}$ , tan .delta., .xi.$_{r}$(분극후)값이 증가하였으며 Qm값과 밀도는 감소하였다. $K_{p}$ 값은 B $i^{3+}$ 가 P $b^{2+}$를 치환하므로 형성되는 Pb공공의 형성에 의해 자발분극이 증가됨에 따라 증가하였다.다.

  • PDF

Effect of Epidural Block under General Anesthesia on Pulse Transit Time (전신마취시 경막외 차단술 병용이 맥파전달시간에 미치는 영향)

  • Choi, Byeong-Cheol;Kim, Seong-Min;Jung, Dong-Keun;Kim, Gi-Ryon;Lee, He-Jeong;Jeon, Gey-Rock
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.25 no.4
    • /
    • pp.262-267
    • /
    • 2005
  • Epidural block under general anesthesia has been widely used to control postoperative pain. In this anesthetic state many hemodynamic parameters are changed. Moreover pulse transit time is influenced by this memodynamic change. m change in the finger and the toe due to relaxation of arterial wall muscle after general anesthesia and epidural block under general anesthesia. This study, in the both general anesthesia and epidural block under general anesthesia, ${\Delta}PTT$ of the toe and of the finger are measured. In addition, ${\Delta}PTT$(toe-finger) of the epidural block under general anesthesia and of the general anesthesia were compared.

Effects of Irradiation and Fumigation on Color and Sensory Properties in the Parts of Dried Red Pepper during Storage (방사선과 훈증 처리된 건고추의 저장 중 부위별 색도 및 관능적 특성)

  • Kim Byeong-Keun;Kwon Youngju;Noh Jungeun;Kim Jeong-Sook;Kim Dong-Ho;Kwon Joong-Ho
    • Food Science and Preservation
    • /
    • v.11 no.4
    • /
    • pp.431-436
    • /
    • 2004
  • Associated with microbial decontamination and quarantine treatment of dried red pepper, the samples was gamma-irradiated (5, 10 kGy) and fumigated (methyl bromide/MeBr, phosphine/$PH_3$) to compare their Hunter's color (L, a, b, ${\Delta}E$) and sensory properties by types (whole, powder, pericarp, seed) during storage under room conditions($18{\pm}12^{\circ}C$). Whole pepper maintained higher lightness (L value) than other groups, while powdered pepper showed higher redness (a value) during storage. Immediately after treatments there was little difference in the overall color difference (${\Delta}E$) among the groups. After 8 months, a higher redness was observed in $PH_3$ group of whole pepper and 5 kGy group of powdered pepper, respectively(p<0.05). Redness of irradiated pericarps was apparently reduced following 8 months of storage and a similar pattern was found in fumigated samples. The yellowness (b value) of pepper seed was lowest in 10 kGy sample (p<0.05), but insignificant difference was observed among treatment groups with storage time. Sensory properties of whole and powdered peppery were little changed by both treatments under commercial conditions. Sensory scores of irradiated or fumigated samples were higher than that of non-treated control with storage time, which was more significant in the powdered than in the whole samples.

The Effect of Auricular Acupuncture at the Shinmun on the Electroencephalogram(EEG) in patients with dementia (이침(耳鍼)의 신문혈(神門穴) 자극(刺戟)이 치매환자(痴呆患者)의 뇌파(腦波)에 미치는 영향(影響))

  • Kim, Mi-Ra;Lee, Go-Eun;Lee, Sang-Eon;Park, In-Sook;Park, Jang-Ho;No, Dong-Jin;Kim, Ji-Young;Park, Bo-Ra;Lyu, Yeoung-Su;Kang, Hyung-Won
    • Journal of Oriental Neuropsychiatry
    • /
    • v.21 no.3
    • /
    • pp.45-64
    • /
    • 2010
  • Objectives : The purpose of this study was to examine the effects of auricular acupuncture at the Shinmun on patients with dementia by using power spectrum analysis. Electroencephalogram(EEG) power spectrum show site-specific and state-related differences in various frequency bands. Methods : Study was carried out in 38 subjects.(31 patients with dementia and 7 normal people, 27 females and 11 males ; mean age=75.9 years old). To know the effect of auricular acupuncture at the Shinmun in patients with dementia, we measured electroencephalogram(EEG) of normal people and patients with dementia about 'before', 'after' and 'after 15 minutes' giving auricular acupuncture at the Shinmun, and compared the brain wave($\alpha$, $\beta$, $\delta$, $\theta$) of EEG 30 channels. Results : In the case of patients with dementia, in the power values of $\alpha$(alpha) band at F4, FP2, FCZ, F8, FC4 channels (p<0.05) during the Shinmun-auricular acupuncture treatment increased significantly. In $\beta$(beta) band, the power values at T8 channel(p<0.05) during the Shinmun-auricular acupuncture treatment increased significantly. In $\delta$(delta) band, the power values at F7, FP1, FZ, FP2, FCZ, C4, FC4, CP4, T8, P7, P3, O1, OZ, O2, P4, P8 channels(p<0.05) during the Shinmun-auricular acupuncture treatment decreased significantly. In $\Theta$(theta) band, the power values at O1, OZ, O2channel(p<0.05) during the Shinmun-auricular acupuncture treatment decreased significantly. Conclusions : Through these results, we concluded that auricular acupuncture at the Shinmun on patients with dementia could have effect the functional mechanism of the cerebral cortex.

Curing Behavior and Adhesion Performance of Urea-Melamine-Formaldehyde (UMF) Resin by Staged Addition of Melamine (멜라민 첨가 순서에 따른 UMF 접착제의 경화거동과 접착력의 영향)

  • Xu, Guang-Zhu;Eom, Young-Geun;Lee, Young-Kyu;Lim, Dong-Hyuk;Lee, Byoung-Ho;Kim, Hyun-Joong
    • Journal of Adhesion and Interface
    • /
    • v.10 no.2
    • /
    • pp.84-89
    • /
    • 2009
  • The objective of this research was to investigate the curing behavior and adhesion performance of urea-melamine-formaldehyde (UMF) resin for the four types of UMF-1, UMF-2, UMF-3, and UMF-4 which synthesized by the staged addition of melamine. Also, various network structures of these resin types were discussed based on their different curing behavior and adhesion performance. The curing behavior was evaluated by DMTA and thermal stability was checked by TGA. Adhesion performance was evaluated by dry and wet shear strengths and the pH value of each cured resin was checked to see its effect on the adhesion performance. The results indicated that the UMF-1 resin type by the addition of melamine initially with the urea and formaldehyde at the same F/(U+M) rate showed the lowest thermal stability, rigidity (${\Delta}E^{\prime}$), temperature of tan ${\delta}$ maximum ($T_{tan}\;_{\delta}$), and wet shear strength, and pH value of cured resin. In wet shear strength, however, the UMF-4 resin type appears to be slightly higher than UMF-1 resin type.

  • PDF

Effects of Qigong therapy on the thermal changes of upper, middle, lower $Danj{\breve{o}}n$(Ex-HN3, CV17, CV4) examined by Digital Infrared Thermographic Imaging(DITI) (기공체조(氣功體操)가 DITI로 촬영한 상(上), 중(中), 하단전(下丹田)의 체표온도(體表溫度)에 미치는 영향(影響))

  • Nam, Sang-Soo;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
    • /
    • v.1 no.1
    • /
    • pp.47-51
    • /
    • 2002
  • Objectives : It is the object of Qigong therapy to promote the circulation of Qi and blood, and to relieve mentality by way of warming lower Danjon. In this study, to prove that Qigong therapy could actually subside heat on upper or middle Danjon and warm the temperature on lower Danjon, we observed the thermal changes of upper, middle, lower Danjon before and after Qigong therapy and compared them. Methods : We selected 16 patients, treated Qigong therapy and examined by D.I.T.I.(Digital Infrared Thermographic Imaging) before and after Qigong therapy, among patients who visited. Qigong clinic, Kangnam Korean hospital, Kyunghee University(Daechi-2dong, Kangnam-Gu) from april to october, 1999. We watched the difference of temperature among upper, middle, lower Danjon before and after Qigong therapy, and used student T-test(paired type, 2 tail) for proving effects of Qigong therapy statistically. Conclusions 1. The difference of temperature$({\Delta}T)$ between upper(Ex-HN3) and lower Danjon(CV4) significantly decreased about $0.55^{\circ}C$ after Qigong therapy(p<0.01). 2. The difference of temperature${\Delta}T$ between middle(CV17) and lower Danjon(CV4) significantly decreased about $0.39^{\circ}C$ after Qigong therapy(p<0.05). 3. The difference of temperature${\Delta}T$ between upper(Ex-HN3) and middle Danjon(CV17) decreased about $0.25^{\circ}C$ after Qigong therapy, but it was not statistically significant.

  • PDF

Citric Acid Production Using Encapsulated Aspergillus niger (Aspergillus niger 고정화 캡슐을 이용한 구연산 생산 특성)

  • 정수환;이태종박중곤장호남
    • KSBB Journal
    • /
    • v.10 no.1
    • /
    • pp.78-88
    • /
    • 1995
  • The encapsulatpd A. niger grew up inside the capsule and mycelia penetrated through the pore of the capsule membrane. The mycelia on the capsule wall became loose when the carbon source and oxygen were deficient in the medium. On the contrary, the production rate increased and mycelia made a lump tightly when the carbon source and oxygen were sufficient. Namely, number of proper capsule of unit volume in the medium was existed. The phenomenon which was swelled of capsule membrane in cultivation could prevented by adding CaCl2 into the medium. According to the time adding CaCl2 into the medium, the production rate of citric acid was influenced. In case of adding CaCl2 into the medium at 7th day cultivation, the production yield of citric acid was increased about 40 percent higher than that of adding CaCl2 initially. The production yield of citric acid using encapsulated A. niger of flask culture was influenced with oxygen supply. The production yield of citric acid ($\Delta$p/$\Delta$s) of the flask culture was increased 3.88 time by using T-flask instead of parafilm sealed flask. Therefore, the productivity and consumption rate concerning production which was taken carbon source were increased when oxygen supply was sufficient. The production of citric acid using encapsulated A. niger was increased average 30 percent higher than that of bead in between 6th and 13th day cultivation.

  • PDF

The Effect of Acupuncture Treatment at the GB37 on the Electroencephalogram(EEG) (광명(GB37) 자침이 뇌파변화에 미치는 영향)

  • Yu, Ik-Han;Lee, Sang-Lyoung
    • Korean Journal of Acupuncture
    • /
    • v.28 no.3
    • /
    • pp.85-98
    • /
    • 2011
  • Objectives : The aim of this thesis is to examine the effect of acupuncture treatment at the GB37 on normal humans by using the power spectral analysis of the EEG. Methods : EEG (Electroencephalogram) power spectrum exhibits site-specific and state-related differences in specific frequency bands. In this thesis, the power spectrum was measured by the complexity. the 32 channels EEG study was carried out in the 13 subjects (12 males ; age=22.58 years old, 1 females ; 22 years old). Results : In the ${\alpha}$ (alpha) band, the power values at F7, F3, F4, F8, FTC2, C4, T4, CP1, CP2, TCP2, TT2, Pz, P4, Po1, Po2, O1, Oz, O2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the ${\beta}$ (beta) band, the power values at Cz, C4, T4, Tcp1, T6, Po1, O1, Oz, O2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the ${\delta}$(delta) band, the power values at Fp1, TT2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the $\theta$ (theta) band, the power values at Fp1, F8, FTC2, Pz channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. Conclusions : This results suggest that the acupuncture treatment at the GB37 significantly mostly change the power spectrum value on the alpha (18 channels), beta (9 channels) bands.