http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
李根茂,李宗錫 홍익대학교 산업기술연구소 2003 産業技術 Vol.13 No.-
In this thesis, the maneuverability characteristic of a ship is predicted when principal dimensions, rudder area and ship speed are given at initial stage of ship design. We assume that external forces (wave, wind, tide) are negligible and substitute ship speed for induced rudder speed. Nomoto equation, is solved to yield the yaw motion, straight stability and Zig-Zag maneuvering. For the purpose of verifying the time constant T and gain constant K, we compare Nomoto's figure to calculated T,K. To verify Zig-Zag maneuvering, we also compare four real Zig-Zag test to calculated values.
李根茂,吳政錫 弘益大學校 産業技術硏究所 2005 産業技術 Vol.15 No.-
The turning circle of a ship is the path followed by her center of gravity in making a turn of 360° degree or more with helm at constant angle. But generally it means her path traced at full angle of the rudder. For the ordinary ship the bow will be inside and the stern outside this circle. It has been usually understood that the turning circle is not essentially affected by ship's speed at Froude numbers less than about 0.3. However, it is recently reported that the speed provide considerable effects upon the turning circle on piloting many ships actually at sea. In this paper, the author analyzed what effects the speed could provide on the turning circle theoretically from the viewpoint of ship motions and examined how the alteration of the speed at Froude no. under 0.30 affect the turning circle actually, through experiments of actual ships of a small and large size.
( Guen Seok Choi ),( Eun Ha Lee ),( Chae Seong Lim ),( Seok Hwa Yoon ) 대한마취과학회 2011 Korean Journal of Anesthesiology Vol.60 No.5
Background: The Glidescope Videolaryngoscope (GVL) is a newly developed video laryngoscope. It offers a significantly improved laryngeal view and facilitates endotracheal intubation in difficult airways, but it is controversial in that it offers an improved laryngeal view in normal airways as well. And the price of GVL is expensive. We hypothesized that intubation carried out by fully experienced anesthesiologists using the GVL with appropriate pre-anesthetic preparations offers an improved laryngeal view and shortened intubation time in normal airways. Therefore, the aim of this study was to compare the GVL with the Macintosh laryngoscope in normal airways and to determine whether GVL can substitute the Macintosh laryngoscope. Methods: This study included 60 patients with an ASA physical status of class 1 or 2 requiring tracheal intubation for elective surgery. All patients were randomly allocated into two groups, GVL (group G) or Macintosh (group M). ADS (airway diffi culty score) was recorded before induction of anesthesia. The anesthesiologist scored vocal cord visualization using the percentage of glottic opening (POGO) visible and the subjective ease of intubation on a visual analogue scale (VAS). The time required to intubate was recorded by an assistant. Results: There was a significant increase in POGO when using the GVL (P < 0.05). However, there was no difference in the time required for a successful tracheal intubation using the GVL compared with the Macintosh laryngoscope. The VAS score on the ease of intubation was significantly lower for the GVL than for the Macintosh laryngoscope (P < 0.05). Conclusions: GVL could be a first-line tool in normal airways. (Korean J Anesthesiol 2011; 60: 339-343)
An Under-Frequency Load Shedding Scheme Design for a Large Steelworks with Self-Generation System
Lee, Sang-Seok,Park, Ji-Ho,Jeong, Ki-Seok,Kim, Heung-Guen The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.5
<P>This paper presents a load-shedding scheme for a large steelworks with several self generation units. The power system of the steelworks can be separated from a utility grid in case of disturbances. Also, some substations with generators in the steelworks can be isolated due to the tie line tripping. These situations cause an under-frequency events as the result of the imbalance between generation and load. A system stabilizing controller (SSC) system is the core of the proposed load shedding scheme for the frequency stabilization. The SSC system performs a pre-calculation for load shedding (LS) quantity before an event and a post-calculation to provide against a deficient load shedding in the pre-calculated load-shedding. The back-up protection system is used to counteract situations in which the SSC system does not operate normally. Also, the load-shedding by frequency calculation is carried out for subsequent disturbance such as an additional generator tripping. The hardware based proposed scheme has been applied to the steelworks. The several under-frequency events causing a load-shedding are examined through the transient stability analysis by using ETAP. The simulation results show that the proposed scheme effectively stabilizes the frequency within the continuous frequency operation range of generators.</P>
An Under-Frequency Load Shedding Scheme Design for a Large Steelworks with Self-Generation System
Sang-Seok Lee,Ji-Ho Park,Ki-Seok Jeong,Heung-Guen Kim 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.5
This paper presents a load-shedding scheme for a large steelworks with several self-generation units. The power system of the steelworks can be separated from a utility grid in case of disturbances. Also, some substations with generators in the steelworks can be isolated due to the tie line tripping. These situations cause an under-frequency events as the result of the imbalance between generation and load. A system stabilizing controller (SSC) system is the core of the proposed load shedding scheme for the frequency stabilization. The SSC system performs a pre-calculation for load-shedding (LS) quantity before an event and a post-calculation to provide against a deficient load-shedding in the pre-calculated load-shedding. The back-up protection system is used to counteract situations in which the SSC system does not operate normally. Also, the load-shedding by frequency calculation is carried out for subsequent disturbance such as an additional generator tripping. The hardware based proposed scheme has been applied to the steelworks. The several under-frequency events causing a load-shedding are examined through the transient stability analysis by using ETAP. The simulation results show that the proposed scheme effectively stabilizes the frequency within the continuous frequency operation range of generators.
Ko, Guen Bae,Yoon, Hyun Suk,Kim, Kyeong Yun,Lee, Min Sun,Yang, Bo Yeun,Jeong, Jae Min,Lee, Dong Soo,Song, In Chan,Kim, Seok-ki,Kim, Daehong,Lee, Jae Sung Society of Nuclear Medicine 2016 The Journal of nuclear medicine Vol.57 No.8
<P>Visualization of biologic processes at molecular and cellular levels has revolutionized the understanding and treatment of human diseases. However, no single biomedical imaging modality provides complete information, resulting in the emergence of multimodal approaches. Combining state-of-the-art PET and MRI technologies without loss of system performance and overall image quality can provide opportunities for new scientific and clinical innovations. Here, we present a multiparametric PET/MR imager based on a small-animal dedicated, high-performance, silicon photomultiplier (SiPM) PET system and a 7-T MR scanner. Methods: A SiPM-based PET insert that has the peak sensitivity of 3.4% and center volumetric resolution of 1.92/0.53 mm(3) (filtered backprojection/ordered-subset expectation maximization) was developed. The SiPM PET insert was placed between the mouse body transceiver coil and gradient coil of a 7-T small-animal MRI scanner for simultaneous PET/MRI. Mutual interference between the MRI and SiPM PET systems was evaluated using various MR pulse sequences. A cylindric corn oil phantom was scanned to assess the effects of the SiPM PET on the MR image acquisition. To assess the influence of MRI on the PET imaging functions, several PET performance indicators including scintillation pulse shape, flood image quality, energy spectrum, counting rate, and phantom image quality were evaluated with and without the application of MR pulse sequences. Simultaneous mouse PET/MRI studies were also performed to demonstrate the potential and usefulness of the multiparametric PET/MRI in preclinical applications. Results: Excellent performance and stability of the PET system were demonstrated, and the PET/MRI combination did not result in significant image quality degradation of either modality. Finally, simultaneous PET/MRI studies in mice demonstrated the feasibility of the developed system for evaluating the biochemical and cellular changes in a brain tumor model and facilitating the development of new multimodal imaging probes. Conclusion: We developed a multiparametric imager with high physical performance and good system stability and demonstrated its feasibility for small-animal experiments, suggesting its usefulness for investigating in vivo molecular interactions of metabolites, and cross-validation studies of both PET and MRI.</P>