Sap Se

Hyosung Heavy Industries Corporation

Samsung Electronics Co., Ltd.

Other

Hyosung Corporation

Joo Yeon Lee

Juchang Lee

Kyu Hwan Kim

Yong Sik Kwon

Seyeong Bae

Mihnea Andrei

Stefan A Baeuerle

Yongsik Yoon

Hyoung Jun Na

Ruediger Karl

Oliver M Steinau

Markus Hartmann

Hong Ju Jung

Eunsang Kim

Sung Min Oh

Kyungyul Park

Myung Sun Park

Jaehwa Kim

Jung Won Hong

Hyun Ho Yoo

Jun Chol Lee

Sunghoon Lee

Chang Gyoo Park

Michael Muehle

Hyeong Seog Kim

Deok Koo Kim

Deok Hoe Kim

Hanggjun Cho

Joongkoo Lee

Hyun Jin Kim

Seung Eun Lee

Ji Hun Kim

Young Keun Lee

Sang Kyun Cha

Jong Hoon Won

Kyung Won Kim

Chul Won Lee

Whan Oh Sung

Sang Hak Lee

Ji Yoon Park

Taehyung Lee

Beomsoo Kim

Jane Jung Lee

Moon Soo Chang

Byung Hwan Jeong

Yong Hee Park

Jong Yun Choi

Doo Young Lee

Byeng Joo Byen

Marcel Birn

Chang Yul Lee

Won Wook Hong

Dong June Kim

Seoyoon Choi

Jong Kyou Jeong

Younkyoung Lee

Jung Soo Park

Various systems and methods for selective revalidation of data objects are provided. In one example, a computer-implemented method includes updating a target data object of a database system according to a definition statement, and determining whether the definition statement changes one or more object properties of the target data object. In response to determining that the definition statement changes the one or more object properties of the target data object, the method includes revalidating data objects depending on the target data object. In response to determining that the definition statement does not change the one or more object properties of the target data object, the method includes not revalidating the data objects depending on the target data object. In this way, database management performance and speed may be improved while maintaining validity of data objects in a database.

Fine-grained decision on propagation of revalidation

The present disclosure provides techniques and solutions for executing requests for database operations involving a remote data source in a system that includes an anchor node and one or more non-anchor nodes. A first request for one or more database operations is received, where at least a first database operation includes a data request for a remote data object. It is determined that the first database operation is not an insert, delete, or update operation, and therefore is assignable to the anchor node or one of the non-anchor nodes. The first database operation is assigned to a non-anchor node for execution. In a particular implementation, for a particular set of requests for a database operation, once an insert, delete, or update operation is received for the remote data object, subsequent operations for the remote data object in the set of requests are assigned to the anchor node for execution.

Flexible routing of database operations accessing remote tables

Proposed is a method for accurately predicting an overcurrent flowing inside an isolated bidirectional DC-DC converter even without using a current sensor on primary and secondary sides of a transformer. In the converter according to the present disclosure, an average value of the inductor current is calculated after deriving inflection point current values by respectively modeling a current waveform for an inductor current of the transformer. A secondary side output current average value is calculated by comparing the calculated average value of the inductor current with a secondary side capacitor current average value of the converter at no load. Next, an error between the secondary side output current average value and an actually measured secondary side output current is calculated, and the inflection point current values of the current waveform are updated using a gain for reducing the error through PI control, whereby the overcurrent may be predicted.

Sensorless prediction method of overcurrent in isolated bidirectional DC-DC converter

Techniques and solutions are described for implementing virtual table schemas. A virtual table schema includes a logical pointer that is used to target a table that includes data and is defined according to the virtual table schema. Values assigned to the logical pointer can be used to target tables at different locations, such as in a federated database system or in a cache of a database management system of a central computing system. When data associated with the virtual table is requested, or prior to receiving the request, the data can be stored in a table in the cache. The logical pointer can be updated to reference the cache. If the cache is full, the table can be removed from the cache, and the logical pointer can be updated to reference a table at the federated database system.

Virtual database tables with updatable logical table pointers

A control device for an MMC is disclosed. The control device for an MMC including a plurality of converter arms that include a plurality of sub-modules connected in series and that are connected to a DC link includes: an arm controller, which detects the arm current of a converter arm so as to determine whether a DC failure has occurred, and, if it is determined that the DC failure has occurred, transmits a bypass control signal for protecting a sub-module and notifies of the DC failure; a sub-module controller for controlling the sub-module so as to bypass a DC failure current according to the bypass control signal received from the arm controller; and a main controller, which detects, in real-time, the arm current of the converter arm and a voltage (DC link voltage) of the DC link, determines whether the DC failure is a temporary DC failure or a permanent DC failure on the basis of the detected arm current and DC link voltage if the occurrence of the DC failure is notified by the arm controller, and transmits, to the arm controller, a normal operation control signal for normal operation of the sub-module or a bypass control signal for bypassing of the DC failure current.

Control device and control method for modular multilevel converter

Techniques and solutions are described for implementing virtual table schemas. A virtual table schema includes a logical pointer that is used to target a table that includes data and is defined according to the virtual table schema. Values assigned to the logical pointer can be used to target tables at different locations, such as in-memory storage or in dynamic storage of a database management system. The dynamic storage includes an in-memory buffer cache and persistent storage. The logical pointer can be updated to point to the in-memory storage or the dynamic storage, including based on use statistics. Similarly, a table having data for the virtual table can be transitioned between the in-memory buffer cache and the persistent storage, including based on use statistics for the virtual table. A value for the logical pointer can be updated when the table is transferred between the in-memory buffer cache and the dynamic storage.

Technologies are described providing adaptive query routing in a replicated database environment. The technologies can be used with a variety of replication protocols. Prepared statements, such as for queries, from a database client can be routed to a source node, or a source node and available replica nodes, when a replica node becomes unavailable. When a replica node becomes available again, a prepared statement can be updated to indicate that the updated prepared statement can be executed at nodes including the replica node that is available again. Prepared statement routing can also be used when a portion of replicated data becomes unavailable at a replica node, but a portion of replicated data remains available.

Adaptive query routing in a replicated database environment

An in-memory database server hosting a tenant of a multi-tenant software architecture can receive a definition of a custom data field that is unique to an organization having isolated access to the tenant. The custom data field can extend a standard table defined by central metadata stored at a system tenant of the multi-tenant software architecture. Tenant private metadata that includes the definition can be stored in memory accessible only to the tenant. A tenant-dependent table that includes the custom data field can be formed, for example by retrieving central metadata defining the standard table from the system tenant and adding the custom data field using the definition. The tenant-dependent table can be presented for access via a database client at the organization. Related systems, articles of manufacture, and computer-implemented methods are disclosed.

In-memory database for multi-tenancy

A method for diagnosing a state of a submodule in initial charging of an MMC converter includes identifying, by an upper level controller, a stopped state of the MMC converter; supplying, by the upper level controller, an alternating current (AC) voltage from an AC side to N submodules in the MMC converter when the MMC converter is in the stopped state; charging a capacitor in the submodule with the supplied AC voltage to store an initial charging voltage in the capacitor; determining, by a submodule controller, whether the submodule is in a fault state and when the submodule is in a fault state, transmitting a fault signal to the upper level controller; and detecting, by a voltage detection unit of the submodule the initial charging voltage stored in the capacitor and transmitting the initial charging voltage to the submodule controller.

Method for diagnosing sub-module state during initial charge of MMC converter

According to an embodiment, a system for calculating air pollutant emission comprises a sensor device installed in an regional section and obtaining a captured image of a vehicle passing through the regional section, an external server storing vehicle specification information, and a management server identifying the vehicle based on the captured image provided from the sensor device, obtaining the vehicle specification information for the identified vehicle from the external server, calculating air pollutant emission for each emission source using the vehicle specification information, and providing statistical information for the air pollutant emission.

Device and method for calculating air pollutant emissions from road mobile source

Technologies are described for performing replication of data within a database environment having a source node and a replica node. The source node executes a database operation on at least one database table stored by the source node. The source node asynchronously sends the database operation to the replica node. A prepare commit request is synchronously sent from the source node to the replica node. The source node receives a synchronous precommit acknowledgement from the replica node. The precommit acknowledgement indicates that the database operation was executed at the replica node. The source node commits a transaction associated with the database operation.

Table replication in a database environment

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Seoul, South Korea

Joo Yeon Lee