Abstract: Disclosed is a display module including a transparent display panel and a frame to fix a side of the transparent display panel, wherein the frame has a communication unit to receive data from the outside, a controller to process the received data and to output a drive command corresponding to the processed data and a display drive unit to drive the transparent display panel in response to the drive command from the controller. A display system includes a system body and a display module detachably mounted in the system body.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Technologies are described for facilitating transaction processing within a database environment. A commit protocol provides for the atomic commit or rollback of a transaction that includes an operation that modifies a metadata entity of the database system and one or more other operations that modify metadata entities or data records of the database system. Innovations are provided for detecting and resolving deadlocks that may arise during transaction processing. Innovations are also provided for providing versioning of metadata entities, including invalidating metadata entities cached at a slave node during the commit at a master node of a transaction that creates a new version of the metadata entity.

Abstract: A physio-logical migration of a database from a source system to a target system may include exporting a catalog of the database in a data interchange format that preserves the hierarchical dependencies present amongst the entities included in the catalog. The physio-logical migration of the database may further include exporting the contents of a table in the database in a binary format compatible at the target system. The binary format may be a data buffer having a metadata portion, a fixed-size portion, and a page chain portion. Where the target system is a cloud-based system, the physio-logical migration of the database may include exporting the catalog and the contents of the table to a cloud-based object store before importing the catalog and the contents of the table to the target system. Related systems and articles of manufacture, including computer program products, are also provided.

Abstract: Disclosed is a display module including a transparent display panel and a frame to fix a side of the transparent display panel, wherein the frame has a communication unit to receive data from the outside, a controller to process the received data and to output a drive command corresponding to the processed data and a display drive unit to drive the transparent display panel in response to the drive command from the controller. A display system includes a system body and a display module detachably mounted in the system body.

Abstract: RTR of a database transaction to a replica table may include receiving replication and transaction commit log entries (representing a database transaction). The replication log entry has a row-ID value, and the row at the replica table has a row-ID value. The replication log entry may be dispatched to a parallel log replayer and the associated transaction commit log entry to a transaction commit log replayer. The row-ID values may be compared, and the replication log entry is replayed at the parallel log replayer based on the comparison. The database transaction may then be committed to the replica table by replaying the associated transaction commit log entry at the transaction log replayer, wherein the database transaction is associated with row-level parallel replay having transactional consistency and DDL replication and reconstruction of a DDL statement at the replica system is associated with one or multiple metadata update log entries.

Abstract: Methods and systems are disclosed for managing replication of metadata in a master-slave database environment. While metadata is managed on a master node using database tables with transaction guarantees, metadata copies on the slave node are managed using a lightweight key-value store. In exemplary embodiments, master metadata database tables are mapped to respective key-value structures at one or more slave nodes. The key-value structures have entries pointing to respective metadata objects, which include copies of metadata items stored in the master metadata database tables. The key-value structures can be hierarchically organized under a parent key-value structure. Metadata object versions can be organized as a linked list to facilitate multi-version concurrency control. Methods are disclosed for building the key-value store, for retrieving metadata from the store, for updating the store, for providing multi-version concurrency control, and for pruning obsolete metadata versions. Variants are disclosed.

Abstract: 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.

Abstract: An MMC converter linked to a HVDC system and a sub-module constituting the MMC converter are proposed. The sub-module includes: first and second power semiconductor switches connected in series in the same direction, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; a capacitor connected in parallel to the first and second power semiconductor switches connected together in series; a first terminal connected to a first node between the first and second power semiconductor switches; a second terminal connected to a second node between the second power semiconductor switch and the capacitor; third and fourth power semiconductor switches connected in series in opposite directions between the first and second terminals, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; and a third terminal connected to a third node between the third and fourth power semiconductor switches.

Abstract: An electronic device and method are disclosed herein. An electronic device includes one or more biometric sensors, a memory configured to store an authentication setting table associated with one or more authentication methods associated with one or more authentication levels, and a processor operatively connected to the memory and the one or more biometric sensors. The processor implements the method, including: receive authentication level information associated with a function executed by the electronic device, select at least one authentication method of the one or more authentication methods matching an authentication level indicated by the received authentication level information, and perform user authentication based on the selected at least one authentication method through the one or more biometric sensors.

Abstract: A method of removing a direct current component at an output terminal of an MMC converter according to the present invention includes a detection step of individually detecting charging voltages charged in capacitors of a plurality of sub-modules connected in series to each other in the MMC converter; outputting an average value of the individually detected charging voltages; delaying the outputted average value by a predetermined phase to output a phase-delayed average value; outputting the average value and the phase-delayed average value as a q-axis component voltage by using a predetermined dq conversion unit; calculating an error between the q-axis component voltage and a three-phase average voltage for the q-axis component voltage; and outputting, through a pre-determined first PI control unit, an offset voltage for reducing the error.

Abstract: Disclosed is a display module including a transparent display panel and a frame to fix a side of the transparent display panel, wherein the frame has a communication unit to receive data from the outside, a controller to process the received data and to output a drive command corresponding to the processed data and a display drive unit to drive the transparent display panel in response to the drive command from the controller. A display system includes a system body and a display module detachably mounted in the system body.

Abstract: 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.

Abstract: RTR of a database transaction to a replica table may include receiving replication and transaction commit log entries (representing a database transaction). The replication log entry has a row-ID value, and the row at the replica table has a row-ID value. The replication log entry may be dispatched to a parallel log replayer and the associated transaction commit log entry to a transaction commit log replayer. The row-ID values may be compared, and the replication log entry is replayed at the parallel log replayer based on the comparison. The database transaction may then be committed to the replica table by replaying the associated transaction commit log entry at the transaction log replayer, wherein the database transaction is associated with row-level parallel replay having transactional consistency and DDL replication and reconstruction of a DDL statement at the replica system is associated with one or multiple metadata update log entries.

Abstract: An MMC converter linked to a HVDC system and a sub-module constituting the MMC converter are proposed. The sub-module includes: first and second power semiconductor switches connected in series in the same direction, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; a capacitor connected in parallel to the first and second power semiconductor switches connected together in series; a first terminal connected to a first node between the first and second power semiconductor switches; a second terminal connected to a second node between the second power semiconductor switch and the capacitor; third and fourth power semiconductor switches connected in series in opposite directions between the first and second terminals, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; and a third terminal connected to a third node between the third and fourth power semiconductor switches.

Abstract: An MMC converter linked to a HVDC system and a sub-module are proposed. The sub-module includes: first and second power semiconductor switches serially connected in the same direction, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; a capacitor parallelly connected to the first and second power semiconductor switches serially connected; a first terminal connected to a first node between the first and second power semiconductor switches; a second terminal connected to a second node between the second power semiconductor switch and the capacitor; a third power semiconductor switch of which a side is connected to the second node, the third power semiconductor switch including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; and a third terminal connected to a terminal of an AC grid system and connected to the other side of the third power semiconductor switch.

Abstract: 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.

Abstract: A method of removing a direct current component at an output terminal of an MMC converter according to the present invention includes a detection step of individually detecting charging voltages charged in capacitors of a plurality of sub-modules connected in series to each other in the MMC converter; outputting an average value of the individually detected charging voltages; delaying the outputted average value by a predetermined phase to output a phase-delayed average value; outputting the average value and the phase-delayed average value as a q-axis component voltage by using a predetermined dq conversion unit; calculating an error between the q-axis component voltage and a three-phase average voltage for the q-axis component voltage; and outputting, through a pre-determined first PI control unit, an offset voltage for reducing the error.