http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Improved Sliding Mode Controller for Shunt Active Power Filter
Sahara, Attia,Kessal, Abdelhalim,Rahmani, Lazhar,Gaubert, Jean-Paul The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3
In this work, nonlinear control of a three-phase shunt active power filter (SAPF) has been studied and compared to classical control based on proportional integral regulator. The control strategy is based on the direct current method using sliding mode control (SMC), where the aim is to regulate the average voltage across the dc bus of the inverter. Details are given for the control algorithm; the controller is comprised of a current loop which utilizes a hysteresis controller to generate the gating signals for the switching devices, and a nonlinear controller based on SMC law which is different from classical laws based on error between reference and measured output voltage of the inverter. Sliding surface applied in this work contains the whole of state variables, in order to ensure full control of the system behavior in the presence of disturbances that affect the supply source, the load parameters or the reference value. The designed controller offers advantage that it can gives the improvement of dynamic and static performances in cases of large disturbances. A comparison of the effects of PI control and SMC on the APF response in steady stat, under line variations, load variations, and different component variations is performed.
Improved Sliding Mode Controller for Shunt Active Power Filter
Attia Sahara,Abdelhalim Kessal,Lazhar Rahmani,Jean-Paul Gaubert 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3
In this work, nonlinear control of a three-phase shunt active power filter (SAPF) has been studied and compared to classical control based on proportional integral regulator. The control strategy is based on the direct current method using sliding mode control (SMC), where the aim is to regulate the average voltage across the dc bus of the inverter. Details are given for the control algorithm; the controller is comprised of a current loop which utilizes a hysteresis controller to generate the gating signals for the switching devices, and a nonlinear controller based on SMC law which is different from classical laws based on error between reference and measured output voltage of the inverter. Sliding surface applied in this work contains the whole of state variables, in order to ensure full control of the system behavior in the presence of disturbances that affect the supply source, the load parameters or the reference value. The designed controller offers advantage that it can gives the improvement of dynamic and static performances in cases of large disturbances. A comparison of the effects of PI control and SMC on the APF response in steady stat, under line variations, load variations, and different component variations is performed.
Ryoji Sahara,Hiroshi Mizuseki,Kaoru Ohno,Yoshiyuki Kawazoe 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.4
Temperature dependence of the bulk modulus in five fcc metals are analyzed by using a fcc lattice-gas model. To treat actual systems as quantitatively as possible, we introduce two empirical potentials, which have been widely used for molecular dynamics (MD) simulations. The potentials are mapped onto the fcc lattice by using the potential renormalization technique, which gives a reasonable way to map interatomic potentials, such as MD potentials, onto lattice models, in order to overcome the shortcomings of lattice-gas models of neglecting the internal entropy of the system. By comparing the results with experimental, MD and first-principles data, the renormalized potential is found to reproduce the temperature dependence of the bulk modulus well. Temperature dependence of the bulk modulus in five fcc metals are analyzed by using a fcc lattice-gas model. To treat actual systems as quantitatively as possible, we introduce two empirical potentials, which have been widely used for molecular dynamics (MD) simulations. The potentials are mapped onto the fcc lattice by using the potential renormalization technique, which gives a reasonable way to map interatomic potentials, such as MD potentials, onto lattice models, in order to overcome the shortcomings of lattice-gas models of neglecting the internal entropy of the system. By comparing the results with experimental, MD and first-principles data, the renormalized potential is found to reproduce the temperature dependence of the bulk modulus well.
Unexpected Complications and Safe Management in Laparoscopic Pancreaticoduodenectomy
Yuichi Nagakawa,Yatsuka Sahara,Yuichi Hosokawa,Chie Takishita,Tetsushi Nakajima,Yousuke Hijikata,Kazuhiko Kasuya,Kenji Katsumata,Akihiko Tsuchida Korean Society of Gastrointestinal Cancer 2017 Journal of digestive cancer reports Vol.5 No.1
Although laparoscopic pancreaticoduodenectomy (LPD) is considered as minimally invasive surgery, an advanced level of laparoscopic skill is still required. LPD comprises various procedures including reconstruction. Therefore, establishment of a safe approach at each step is needed. Prevention of intraoperative bleeding is the most important factor in safe completion of LPD. The establishment of effective retraction methods is also important at each site to prevent vascular injury. I also recommend the "uncinate process first" approach during initial cases of LPD, in which the branches of the inferior pancreaticoduodenal artery are dissected first, at points where they enter the uncinate process. This approach is performed at the left side of the superior mesenteric artery (SMA) before isolating the pancreatic head from the right aspect of the SMA, which allows safe dissection without bleeding. Safe and reliable reconstruction is also important to prevent postoperative complications. Laparoscopic pancreatojejunostomy requires highly skilled suturing technique. Pancreatojejunostomy through a small abdominal incision, as in hybrid-LPD, facilitates reconstruction. In LPD, the surgical view is limited. Therefore, we must carefully verify the position of the pancreaticobiliary limb. A twisted mesentery may cause severe congestion of the pancreaticobiliary limb following reconstruction, resulting in severe complications. We must secure the appropriate position of the pancreaticobiliary limb before starting reconstruction. We describe the incidence of intraoperative and postoperative complications and appropriate technique for safe performance of LPD.
Kazunori Itoh,Shingo Saito,Shunsaku Sahara,Yuki Naitoh,Kenji Imai,Hiroshi Kitakoji 사단법인약침학회 2014 Journal of Acupuncture & Meridian Studies Vol.7 No.2
There is evidence for the efficacy of acupuncture treatment for chronic shoulder pain, but it remains unclear which acupuncture modes are most effective. We compared the effect of trigger point acupuncture (TrP), with that of sham (SH) acupuncture treatments, on pain and shoulder function in patients with chronic shoulder pain. The participants were 18 patients (15 women, 3 men; aged 42e65 years) with nonradiating shoulder pain for at least 6 months and normal neurological findings. The participants were randomized into two groups, each receiving five treatment sessions. The TrP group received treat- ment at trigger points for the muscle, while the other group received SH acupuncture treatment on the same muscle. Outcome measures were pain intensity (visual analogue scale, VAS) and shoulder function (ConstanteMurley Score: CMS). After treatment, pain intensity between pretreatment and 5 weeks after TrP decreased significantly (p < 0.001). Shoulder function also increased significantly between pretreatment and 5 weeks after TrP (p < 0.001). A comparison using the area under the outcome curves demonstrated a significant difference between groups (p Z 0.024). Compared with SH acupuncture therapy, TrP therapy appears more effective for chronic shoulder pain.