BACKGROUND Solid pseudopapillary neoplasm(SPN)of the pancreas is a rare epithelial tumor that primarily affects young women.Since the condition is often asymptomatic or presents with non-specific symptoms,its diagnosi...BACKGROUND Solid pseudopapillary neoplasm(SPN)of the pancreas is a rare epithelial tumor that primarily affects young women.Since the condition is often asymptomatic or presents with non-specific symptoms,its diagnosis can be difficult.CASE SUMMARY This report details the case of a 15-year-old girl who presented with a 2-year history of abdominal pain,with no significant findings during physical examination.Abdominal ultrasound revealed a well-defined heterogeneous solidcystic mass in the epigastric region,likely originating from the tail of the pancreas.A subsequent contrast-enhanced computed tomography scan indicated a welldefined cystic lesion with an enhancing solid component and capsule in the tail of the pancreas,suggestive of a cystic neoplasm.The patient underwent an open distal pancreatectomy with splenectomy,and histopathological analysis confirmed the diagnosis of SPN of the pancreas.CONCLUSION This case highlights the risk of SPN in adolescent girls and the necessity of early diagnosis and intervention for better outcomes.展开更多
System operators and planners develop and implement restoration plans based on off-line simulation studies, and accumulated experience and knowledge. One of the challenges in developing a restoration plan is to sift t...System operators and planners develop and implement restoration plans based on off-line simulation studies, and accumulated experience and knowledge. One of the challenges in developing a restoration plan is to sift through numerous possible restoration scenarios and paths, in order to identify those that are technically feasible. When implementing a restoration plan in an on-line environment following a blackout, the operators need to adapt to the actual outage scenarios and available resources, and be constantly mindful of anticipated voltage and frequency excursions that must remain within system and equipment tolerances. In recognition of these challenges, EPRI has developed System Restoration Navigator (SRN), to provide decision support to system restoration planning and operations engineers in developing, evaluating and revising system restoration strategies, guidelines, plans and step-by-step procedures. During 2013-2014, EPRI developed SRN version 3.0, which is designed to facilitate its integration into a commercial operator training simulator (OTS) (AKA a dispatch training simulator, DTS). The integration of SRN 3.0 with an OTS allows operators to obtain experience in simulating, developing, experimenting with and revising system restoration plans, and to address related regulatory standards. The integration expands the usability of SRN 3.0 by providing the OTS platform for training purposes and for the purpose of interfacing SRN 3.0 with operational power system models to be able to explore near real time application of SRN 3.0. This 2013-2014 development work also included the integration of SRN 3.0 into EPRI OTS, and its application on the Florida Reliability Coordinating Council (FRCC) power system. A detailed account of development of SRN 3.0, its integration into EPRI OTS and its application to FRCC system is presented in this paper.展开更多
Early warning of impending instability in a power system under disturbance conditions is important for preventing of system collapse.A measurement-based approach is proposed to assess the potential power system transi...Early warning of impending instability in a power system under disturbance conditions is important for preventing of system collapse.A measurement-based approach is proposed to assess the potential power system transient instability problem under cascading outages.Where a measurement-based index is obtained as the estimation accuracy of a linear autoregressive exogenous(ARX)model to estimate the dynamic response of the power system and indicate the system stability to some extent after a disturbance.The proposed approach was verified using a set of marginally stable cases in a 179-bus WECC equivalent power system.Then the instability early warning threshold for this system is obtained as 0.44.展开更多
文摘BACKGROUND Solid pseudopapillary neoplasm(SPN)of the pancreas is a rare epithelial tumor that primarily affects young women.Since the condition is often asymptomatic or presents with non-specific symptoms,its diagnosis can be difficult.CASE SUMMARY This report details the case of a 15-year-old girl who presented with a 2-year history of abdominal pain,with no significant findings during physical examination.Abdominal ultrasound revealed a well-defined heterogeneous solidcystic mass in the epigastric region,likely originating from the tail of the pancreas.A subsequent contrast-enhanced computed tomography scan indicated a welldefined cystic lesion with an enhancing solid component and capsule in the tail of the pancreas,suggestive of a cystic neoplasm.The patient underwent an open distal pancreatectomy with splenectomy,and histopathological analysis confirmed the diagnosis of SPN of the pancreas.CONCLUSION This case highlights the risk of SPN in adolescent girls and the necessity of early diagnosis and intervention for better outcomes.
文摘System operators and planners develop and implement restoration plans based on off-line simulation studies, and accumulated experience and knowledge. One of the challenges in developing a restoration plan is to sift through numerous possible restoration scenarios and paths, in order to identify those that are technically feasible. When implementing a restoration plan in an on-line environment following a blackout, the operators need to adapt to the actual outage scenarios and available resources, and be constantly mindful of anticipated voltage and frequency excursions that must remain within system and equipment tolerances. In recognition of these challenges, EPRI has developed System Restoration Navigator (SRN), to provide decision support to system restoration planning and operations engineers in developing, evaluating and revising system restoration strategies, guidelines, plans and step-by-step procedures. During 2013-2014, EPRI developed SRN version 3.0, which is designed to facilitate its integration into a commercial operator training simulator (OTS) (AKA a dispatch training simulator, DTS). The integration of SRN 3.0 with an OTS allows operators to obtain experience in simulating, developing, experimenting with and revising system restoration plans, and to address related regulatory standards. The integration expands the usability of SRN 3.0 by providing the OTS platform for training purposes and for the purpose of interfacing SRN 3.0 with operational power system models to be able to explore near real time application of SRN 3.0. This 2013-2014 development work also included the integration of SRN 3.0 into EPRI OTS, and its application on the Florida Reliability Coordinating Council (FRCC) power system. A detailed account of development of SRN 3.0, its integration into EPRI OTS and its application to FRCC system is presented in this paper.
基金supported by Electric Power Research Institute and also made use of Engineering Research Center Shared Facilities supported by the DOE under NSF Award Number EEC1041877 and the CURENT Industry Partnership Program.
文摘Early warning of impending instability in a power system under disturbance conditions is important for preventing of system collapse.A measurement-based approach is proposed to assess the potential power system transient instability problem under cascading outages.Where a measurement-based index is obtained as the estimation accuracy of a linear autoregressive exogenous(ARX)model to estimate the dynamic response of the power system and indicate the system stability to some extent after a disturbance.The proposed approach was verified using a set of marginally stable cases in a 179-bus WECC equivalent power system.Then the instability early warning threshold for this system is obtained as 0.44.
