In LTE a measurement configuration message, which instructs a terminal (10, 11, 12) on when to transmit a measurement report, is per frequency carrier dependent. A measurement object configuration for 5G/NR wireless communication is provided which is independent of carrier frequency, allowing multiple measurement objects to be configured for one particular carrier frequency. Each measurement object can be defined over a particular time duration (T1, T2, T3), frequency range, time/frequency grid, beam, and/or a particular frequency carrier (Layer 1, Layer 2) in order to satisfy various requirements on RRM measurement of NR. Thus, for a particular terminal (10, 11, 12) and a particular carrier frequency, a base station (20, 21, 22, 23) can define multiple measurement objects over different time/frequency grids.

Wireless communication systems are widely known in which terminals (also called user equipments or UEs, subscriber or mobile stations) communicate with base stations (BSs) within communication range of the terminals.
The wireless communication system typically employs a given carrier frequency (also referred to below as "frequency layer" or "component"). The different geographical areas served by one or more BSs are generally referred to as cells, and typically many BSs are provided in appropriate locations so as to form a network covering a wide geographical area more or less seamlessly with adjacent and/or overlapping cells. (In this specification, the terms "system" and "network" are used synonymously). Each BS may support one or more cells and in each cell, the BS divides the available bandwidth, i.e. frequency and time resources, into individual resource allocations for the UEs which it serves. In this way, a signal transmitted in the cell and scheduled by the BS has a specific location in the frequency and time domains. The terminals are generally mobile and therefore may move among the cells, prompting a need for handovers between the BSs of adjacent cells. A terminal may be in range of (i.e. able to detect signals from and/or communicate with) several cells at the same time, but in the simplest case it communicates with one "serving" cell.
Current, "4G" systems include those based on the set of standards referred to as Long-Term Evolution or LTE, produced by the 3rd Generation Partnership Project (3GPP), and in which terminals are referred to as UEs (user equipments) and base stations include so-called eNBs (evolved NodeB). LTE supports frequency-division duplex (FDD), where uplink and downlink transmission are separated in frequency, as well as time-division duplex (TDD), where uplink and downlink are separated in time. LTE uses orthogonal frequency-division multiplexing (OFDM), which divides the available system bandwidth into multiple orthogonal subcarriers in the frequency domain and into multiple OFDM symbols in the time domain. It is expected that future 5G/NR systems will likewise employ OFDM. Base stations (eNBs in LTE) are proposed to be referred to as "gNB" in 5G/NR.
Nowadays mobile access to Internet or another mobile point is becoming a crucial necessity for both business and personal life and there are significant challenges to the current wireless systems due to the popularity of new applications such as social networking, cloud based services and big data analysis. With the forthcoming services such as Internet of things and ultra-reliable, mission-critical connections, a next-generation Radio Access Technology (RAT) to succeed LTE/LTE-A and known as "5G" or "NR" (New Radio) will be needed to satisfy all those demanding requirements. FIG. 1 illustrates the demands which 5G systems will be required to meet (source: "Looking ahead to 5G", Nokia White Paper).
As shown in FIG. 1, simultaneous requirements to be met comprise greatly increased traffic; many more devices; reduced latency; low-power and low-cost solutions for Machine-to-Machine (M2M) devices; and increased peak and guaranteed data rates. The intention of 5G is to satisfy all requirements of these applications and ideally, 5G could provide at least the following features:                Ultra-reliable connection in addition to higher data rate, higher capacity and higher spectral efficiency;        Unified user experience together with significant reduction on latency;        Scalability/adaptability to applications with significant different Quality of Service (QoS) requirements;        Access all spectrum and bands and support different spectrum sharing schemes.
From the properties of traffic profiles point of view, 5G is to support three profiles with significant different properties, namely:
(i) high throughput with high mobility traffic;
(ii) low-energy consumption and long lived sensor-based services; and
(iii) extremely low latency and high reliability services.
From the industry point of view, 5G will not only provide traditional voice and data services but also expand and penetrate to other industries such as automotive, agriculture, city management, healthcare, energy, public transportation etc., and all these will lead to a large ecosystem which has never experienced before.
The technical challenges for designing such a sophisticated and complicated system are tremendous and significant breakthroughs will be required both on the network side and in the radio interface. Regarding the physical layer of the radio interface, a few new techniques will be introduced in order to support aforementioned 5G requirements. One important objective of studies in 3GPP is to investigate fundamental physical layer designs such as waveform design, basic numerology and frame structure, channel coding scheme(s) and so on to meeting key 5G requirements.
From a spectrum point of view, in the longer term, much more spectrum will be available to meet traffic demand. Nowadays, spectrum for mobile communication has focused on the frequencies below 6 GHz. In the time frame of 2020 to 2030, more spectrum at the high frequencies such as 6 GHz, 10 GHz or even up to 100 GHz will be considered. At the same time larger bandwidth spectrum will be available at these extreme higher frequency bands.
More detailed information is provided in Table 1 (source: Ofcom, "Spectrum above 6 GHz for future mobile communications", February 2015).
TABLE 1Possible spectrum allocation for 5G and beyondSpectrumPossible allocation 5 GHzThis band is being considered at the ITU World Radio Conference in2015 (WRC-15) - in total over 300 MHz in new spectrum could beallocatedIf agreed at WRC-15, a contiguous band from 5150 to 5925 MHzwould be created using a combination of existing and new spectrumChannel sizes likely based on current Wi-Fi use, in multiples of20 MHz, and the band may remain as a licence-exempt band in linewith current Wi-Fi15 GHzPotentially over 500 MHz contiguous spectrum depending on the sub-band used and sharing with existing usesVery high speeds are achievable - for example, peak speeds of5Gbps have been demonstrated alreadyChannel sizes could be very wide, for example, multiples of 100 MHz28 GHzSimilar to the 15 GHz band, for example, over contiguous 500 MHz ofspectrum depending on the sub-band used and sharing with existingusesChannel sizes could be very wide, for example, multiples of 100 MHzDepending on the bandwidth available, the band could accommodatemultiple operators with the opportunity for companies other thanestablished mobile operators to offer some 5G services with anassignment of 100 MHz per operator, or more, depending on nationalavailability and sharing with existing services.60-80 GHz  Potentially up to 5 GHz of contiguous spectrum depending on theselected sub-band (for example, 71-76 MHz and/or 81-86 GHz)Channel sizes could be very wide, for example, multiples of 100 MHzDepending on the bandwidth available, the band could accommodatemultiple operators with the opportunity for companies other thanestablished mobile operators to offer some 5G services with a100 MHz assignment per operator, or more, depending on nationalavailability and sharing with existing services.
The radio propagation characteristics at the extreme high frequencies such as spectrum above 6 GHz, brings more challenges compared with that of spectrum at 2 GHz, which is the typical spectrum of 3G/4G. These challenges are the large free space loss, poor penetration/scattering properties and possible non-existing line of light path. Despite these challenges, extreme high frequencies also have their advantages such as large bandwidth availability. Carrier spacings may be adapted to suit the bandwidth(s) available.
Another advantage of high frequencies is that the size of antennas can be small, which means dense antenna array is more feasible to be used for extreme high frequency scenario. With dense antenna array, it is easily for a mobile network to exploit benefits of beam-forming technique. Digital beamforming and analog beamforming are two typical types of beamforming. Theoretically, the difference between them is at a particular time instance the analog beamforming builds a single beam using several tens of antennas, to cover a limited area with smaller power consumption and hardware usage; whereas digital beamforming can have multiple beams to cover a relative wide area with more power consumption and more hardware cost. Sometimes the network can use these two beamforming techniques simultaneously.
The possibility of using various frequency bands leads to the concept of "numerology". This is a special term used for NR to describe a set of parameters for OFDM. For example numerology 1 has a 15 KHz carrier spacing, a particular OFDM symbol period and a particular cyclic prefix length. "numerology 2" may have a 30 kHz carrier spacing, a particular OFDM symbol length (with is half of that of the numerology with 15 kHz), a particular cyclic prefix length.
Returning to the LTE system, in the frequency domain transmissions occur within at least one frequency band and in the time domain, transmission is organized in "frames" which are subdivided into "subframes". In one frame structure used in LTE, a 10 ms frame is divided into 10 subframes each of 1 ms duration, as illustrated in the top left-hand corner of FIG. 2. Below the frame in FIG. 2, one subframe is shown having a duration of two slots, each slot consisting (in this example) of six physical resource blocks (PRBs). More generally, depending on the system bandwidth, anywhere between 6 and 110 PRB pairs compose each 1 ms subframe. The right-hand part of FIG. 2 illustrates one PRB pair as a resource grid with time (symbols) along the horizontal-axis and frequency (subcarriers) along the vertical-axis. Each PRB extends over seven OFDM symbols in the time domain and twelve subcarriers in the frequency domain. Thus, each PRB pair provides a total of 14*12 distinct time/frequency locations represented by the small squares in the Figure. More generally, any arbitrary area on a resource grid like that of FIG. 3—in other words a set of resources extending in both time and frequency domains—is referred to below as a time/frequency grid.
As part of Radio Resource Management (RRM), terminals need to measure each communication channel between itself and a given cell in order to provide appropriate feedback to that cell. To facilitate measurements of the channel by terminals, reference signals are transmitted by the cells. Various kinds of reference signal (or symbol) are provided in LTE, but for present purposes the most notable are the Cell-specific Reference Signal (CRS), which is cell specific and available to all terminals in a cell, a Channel State Information Reference Signal CSI-RS used by a terminal to report CSI feedback, and a discovery reference signal (DRS), used to replace the CRS when a cell is in the off mode. In order to support mobility functionality within LTE, a terminal will perform RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) measurement, both are based on the cell-specific reference signal (CRS). Such measurements provide the UE with the capability of timely detection and identification of the best suitable network nodes available for potential connection. In addition they allow the network to get the information regarding the radio conditions that a particular UE is experiencing. In LTE, measurement activities is controlled by UE under the RRC_IDLE state and within RRC_CONNECTED state, measurement is configured by eNB and a terminal will follow eNB's instruction to perform measurement.
The CRSs are transmitted on certain resources in every PRB and every subframe. Within the PRB pair, as shown in the resource grid at the right-hand side of FIG. 2, the CRS are distributed in a predetermined pattern. The locations of individual reference symbols are marked as R0, R1, R2 and R3. Incidentally, a distinction may be drawn between a "reference symbol", and a "reference signal" which can be defined as a set or pattern of reference symbols. However the two terms are often used synonymously.
Except for shifts at the frequency domain, the CRS pattern of a particular antenna port is identical over the full system bandwidth and repeats itself over the time domain. When a UE is in RRC_CONNECTED state, when and how to execute measurement is controlled by eNB through measurement configuration. The measurement configuration is sent to the UE by means of dedicated signalling, typically using the "RRCConnectionReconfiguration" message.
The measurement configuration message sent to the UE includes the following key components:                Measurement objects: The objects on which the UE shall perform the measurements; i.e. frequencies and cells. In other words: what should the UE measure? These include intra- and inter-frequency neighbours in the LTE network, and possibly also objects in networks of other RATs such as UMTS (Universal Mobile Telecommunication System) or GSM (Global System for Mobile Communications).        Reporting configurations: A list of reporting configurations, in other words the criteria used by the UE to trigger the transmission of a measurement report and the quantities that the UE includes in the report. The reporting configurations define when should the UE send a report. The trigger can either be periodical or event-based. Each reporting configuration consists of the following:                    Reporting criterion: The criterion that triggers the UE to send a measurement report. This can either be periodical or a single event description.            Reporting format: The quantities that the UE includes in the measurement report and associated information (e.g. number of cells to report).                        Measurement identities: the UE needs to keep track of the objects to be measured and their specific triggers; therefore it maintains a list of measurement identities where each measurement identity links one measurement object with one reporting configuration. The measurement identity is used as a reference number in the measurement report. By configuring multiple measurement identities it is possible to link more than one measurement object to the same reporting configuration, as well as to link more than one reporting configuration to the same measurement object. Each measurement identity (MID) is configured to link one measurement object (MO) with one measurement reporting configuration (RC) and is used as a reference number in the measurement report. So by configuring multiple MIDs in LTE, it is possible to link more than one MO to the same RC, as well as to link more than one RC to the same MO, which is illustrated in FIG. 3.
The UE maintains a single measurement object list, a single reporting configuration list and a single measurement identities list. Any measurement object can be linked to any reporting configuration of the same Radio Access Technology (RAT) type.
As mentioned earlier, a report can be event-triggered or periodical. As FIG. 3 shows, each RC includes an "event" representing the above mentioned trigger for transmission of a measurement report. The measurement report will be transmitted when the criteria for any of the following events have been met:
A1: Serving Cell becomes better than a defined threshold
A2: Serving Cell becomes worse than a defined threshold
A3: Neighbor cell becomes some offset better than the primary cell
A4: Neighbor cell becomes better than a defined threshold
A5: Primary cell becomes worse than a defined threshold and a neighbor becomes better than a second threshold
A6: Neighbor cell becomes some offset better than the serving cell
B1: Inter-RAT neighbor becomes better a defined threshold
B2: Primary cell becomes worse than a defined threshold and inter-RAT neighbor becomes better than a second threshold
The UE performs measurements at the physical layer, Layer 1, and it reports them to the Layer 3 (network). The 3GPP specifications contain information about the accuracy of the measurements. These accuracy specifications are part of the Layer 1 filtering of the measurements prior to sending a report, usually performed over a period of 200 ms. In order to improve the measurements accuracy and mitigate the effects of fading, Layer 3 filtering is applied to the physical layer measurements. Thus the raw measurements from Layer 1 are further averaged at Layer 3. The updated filtered measurement result is used for evaluating the reporting criteria or for measurement reporting.
Periodical measurement reports are sent based on the reporting configuration. For instance, it could be configured that the UE report its transmit power every 2 seconds or its transport channel block error rate every second.
To explain measurement object configuration in more detail, in LTE the format to define a measurement object configuration (as specified in 3GPP TS 36.331) is called ASN.1, a formal notation used for describing data transmitted by telecommunications protocols. The definition of ASN.1 can be found at http://www.itu.int/en/ITU-T/asn1/Pages/introduction.aspx.
Some relevant parts of the specification and the conventional measurement object configuration in LTE, "MeasObjectEUTRA", followed by definitions of the various constituent fields of the configuration, are given below.                Field identifiers shall start with a lowercase letter and use mixed case thereafter, e.g., establishmentCause. If a field identifier begins with an acronym (which would normally be in upper case), the entire acronym is lowercase (plmn-Identity, not pLMN-Identity). The acronym is set off with a hyphen (ue-Identity, not ueIdentity), in order to facilitate a consistent search pattern with corresponding type identifiers.                    Identifiers that are likely to be keywords of some language, especially widely used languages, such as C++ or Java, should be avoided to the extent possible.
MeasObjectEUTRA ::=SEQUENCE {carrierFreqARFCN-ValueEUTRA,allowedMeasBandwidthAllowedMeasBandwidth,presenceAntennaPort1PresenceAntennaPort1,neighCellConfigNeighCellConfig,offsetFreqQ-OffsetRangeDEFAULT dB0,-- Cell listcellsToRemoveListCellIndexListOPTIONAL,-- NeedONcellsToAddModListCellsToAddModListOPTIONAL,-- NeedON-- Black listblackCellsToRemoveListCellIndexListOPTIONAL,--Need ONblackCellsToAddModListBlackCellsToAddModListOPTIONAL,-- Need ONcellForWhichToReportCGIPhysCellIdOPTIONAL,--Need ON...,[[measCycleSCell-r10MeasCycleSCell-r10OPTIONAL,-- NeedONmeasSubframePatternConfigNeigh-r10 MeasSubframePatternConfigNeigh-r10OPTIONAL-- Need ON]],[[widebandRSRQ-Meas-r11BOOLEAN OPTIONAL-- Cond WB-RSRQ]],[[altTTT-CellsToRemoveList-r12CellIndexListOPTIONAL,-- NeedONaltTTT-CellsToAddModList-r12AltTTT-CellsToAddModList-r12OPTIONAL,--Need ONt312-r12CHOICE {releaseNULL,setupENUMERATED {ms0, ms50, ms100, ms200,ms300, ms400, ms500, ms1000}}OPTIONAL,-- Need ONreducedMeasPerformance-r12BOOLEANOPTIONAL,--Need ONmeasDS-Config-r12MeasDS-Config-r12OPTIONAL--Need ON]],[[whiteCellsToRemoveList-r13CellIndexListOPTIONAL,--Need ONwhiteCellsToAddModList-r13WhiteCellsToAddModList-r13OPTIONAL,-- Need ONrmtc-Config-r13RMTC-Config-r13OPTIONAL,-- Need ONcarrierFreq-r13ARFCN-ValueEUTRA-v9e0OPTIONAL-- Need ON]]}CellIndexList ::=SEQUENCE (SIZE (1..maxCellMeas)) OF CellIndexCellIndex ::=INTEGER (1..maxCellMeas)
In the above, ARFCN means the possible location where a carrier centre locates. The Q-offset is some offset value of a cell, which is used for a few scenarios such as cell reselection in the RRC_idle state. The intention is to setup some priority of some cells. For example when the power of Cell 1 is larger than Cell 2, a UE will camp on Cell 1. With the offset value it can be arranged that when the power of Cell 1>Cell 2+offset value, then a UE can camp on Cell 1. Default dB0 means that the default value of the offset is 0 dB.
PresenceAntennaPort1 indicates whether antenna port 1 is in use and takes the value either 0 or 1. NeighCellConfig provides information related to MBSFN and TDD UL/DL configuration of neighbour cells of this frequency. Further definitions are provided by the following Table.
MeasObjectEUTRA field descriptionsaltTTT-CellsToAddModListList of cells to add/modify in the cell list for which the alternative time to trigger specifiedby alternativeTimeToTrigger in reportConfigEUTRA, if configured, applies.altTTT-CellsToRemoveListList of cells to remove from the list of cells for alternative time to trigger.blackCellsToAddModListList of cells to add/modify in the black list of cells.blackCellsToRemoveListList of cells to remove from the black list of cells.carrierFreqIdentifies E-UTRA carrier frequency for which this configuration is valid. E-UTRAN doesnot configure more than one measurement object for the same physical frequencyregardless of the E-ARFCN used to indicate this. CarrierFreq-r13 is included only whenthe extension list measObjectToAddModListExt-r13 is used. If carrierFreq-r13 ispresent, carrierFreq (i.e., without suffix) shall be set to value maxEARFCN.cellIndexEntry index in the cell list. An entry may concern a range of cells, in which case thisvalue applies to the entire range.cellIndividualOffsetCell individual offset applicable to a specific cell. Value dB-24 corresponds to −24 dB,dB-22 corresponds to −22 dB and so on.cellsToAddModListList of cells to add/modify in the cell list.cellsToRemoveListList of cells to remove from the cell list.measCycleSCellThe parameter is used only when an SCell is configured on the frequency indicated bythe measObject and is in deactivated state, see TS 36.133 [16, 8.3.3]. E-UTRANconfigures the parameter whenever an SCell is configured on the frequency indicated bythe measObject, but the field may also be signalled when an SCell is not configured.Value sf160 corresponds to 160 sub-frames, sf256 corresponds to 256 sub-frames andso on.measDS-ConfigParameters applicable to discovery signals measurement on the carrier frequencyindicated by carrierFreq.measDurationNumber of consecutive symbols for which the Physical Layer reports samples of RSSI,see TS 36.214 [48]. Value sym1 corresponds to one symbol, sym14 corresponds to 14symbols, and so on.measSubframeCellListList of cells for which measSubframePattemNeigh is applied.measSubframePatternNeighTime domain measurement resource restriction pattern applicable to neighbour cellRSRP and RSRQ measurements on the carrier frequency indicated by carrierFreq. Forcells in measSubframeCellList the UE shall assume that the subframes indicated bymeasSubframePattemNeigh are non-MBSFN subframes, and have the same specialsubframe configuration as PCell.offsetFreqOffset value applicable to the carrier frequency. Value dB-24 corresponds to −24 dB, dB-22 corresponds to −22 dB and so on.physCellIdPhysical cell identity of a cell in the cell list.physCellIdRangePhysical cell identity or a range of physical cell identities.reducedMeasPerformanceIf set to TRUE, the EUTRA carrier frequency is configured for reduced measurementperformance, otherwise it is configured for normal measurement performance, see TS36.133 [16].rmtc-ConfigParameters applicable to RSSI and channel occupancy measurement on the carrierfrequency indicated by carrierFreq.rmtc-PeriodIndicates the RSSI measurement timing configuration (RMTC) periodicity for thisfrequency. Value ms40 corresponds to 40 ms periodicity, ms80 corresponds to 80 msperiodicity and so on, see TS 36.214 [48].rmtc-SubframeOffsetIndicates the RSSI measurement timing configuration (RMTC) subframe offset for thisfrequency. The value of rmtc-SubframeOffset should be smaller than the value of rmtc-Period, see TS 36.214 [48]. For inter-frequency measurements, this field is optionalpresent and if it is not configured, the UE chooses a random value as rmtc-SubframeOffset for measDuration which shall be selected to be between 0 and theconfigured rmtc-Period with equal probability.t312The value of timer T312. Value ms0 represents 0 ms, ms50 represents 50 ms and soon.widebandRSRQ-MeasIf this field is set to TRUE, the UE shall, when performing RSRQ measurements, use awider bandwidth in accordance with TS 36.133 [16].whiteCellsToAddModListList of cells to add/modify in the white list of cells.whiteCellsToRemoveListList of cells to remove from the white list of cells.
As can be seen from the above Table, the measurement configuration may include a white cell list and black cell list, respectively identifying cells which a UE should measure (white list) and should not measure (black list). From the configuration, a UE will automatically identify suitable cells (including cells not listed within the measurement configuration) to be measured and report the measurement result.
The above passages have summarised the arrangements for measurement reporting using CRS in LTE. However, due to new deployment scenarios, a new design philosophy and new technologies especially considering the beamforming technique, the design of reference symbols of NR could be significantly different compared with LTE CRS design. To guarantee meaningful and efficient NR RRM measurement, the measurement configuration information of NR has to be significantly updated as well.
FIG. 4 shows an example of an LTE system in which a first base station 21 provides a first cell, Cell 1; a second base station 22 provides a second cell, Cell 2; and a third base station provides a third cell, Cell 3. A first UE 11 is camping on Cell 1 and a second UE 12 is camping on Cell 2. Cell 1, Cell 2 and Cell 3 belong to the same operator and therefore employ the same frequency carrier (layer/component). The resource grid RG in FIG. 4 shows the CRS from antenna port 0 of one cell. As in FIG. 2, "R" indicates the location of a reference symbol in one PRB pair. Locations marked "X" denote reference symbol positions for antenna port 1 of the same cell. Although the Figure shows only one PRB pair, as already mentioned the reference signals cover the whole operating bandwidth and are repeated periodically in the time domain.
The provision of reference symbols incurs a certain "overhead"; that is, the number of reference symbols against the total available resource. As shown in FIG. 4, within 2 PRBs for antenna port 0 there are 8 reference symbols "R". As a fraction of the total number of time/frequency locations in the PRB pair, therefore, the overhead is 8/(14*12). If the number of reference symbols could be reduced, the overhead will be reduced.
UE 11 and UE 12 will perform RRM measurements (RSRP or RSRQ) based on the cell specific reference signal. The pattern of cell-specific reference signal of antenna port 0 of two PRBs is shown in the small picture at the right hand side within FIG. 4. Since the same pattern will repeat over the time domain and full system bandwidth, a UE will follow a consistent measurement process irrespective of the beginning point and the end point at the time domain, and irrespective of the location at the frequency domain, of measurement; and the measurement results will not be distorted if further processed by a Layer 1 (L1) or Layer 3 (L3) filtering.
The network operator is licensed to use a particular frequency band or carrier, referred to henceforth as a frequency layer/component. Therefore the fundamental unit of the measurement object in measurement configuration information in LTE is the particular frequency layer/component. The time, frequency or the spatial information does not need to be included in the measurement configuration message in LTE because it is assumed that the UE will measure all CRS in the same way.
FIG. 5 shows an example of a NR system where UE 11 is camping on Cell 1 and UE 12 is camping on Cell 2. Cell 1, Cell 2 and Cell 3 belong to the same frequency carrier. It is assumed that each cell will employ the above mentioned analog or digital beamforming technique, and that the beamforming pattern (the number and the direction of beams) will change within different time periods T1 and T2 as shown in the Figure.
As in LTE, the UEs will need to perform measurements on reference signals. It can be expected that these reference signals will include CRS as in LTE (or their equivalent). However, new reference signals may be introduced, for example beam-specific reference signals corresponding to individual beams from cells via analog or digital beamforming. Use of beam-specific reference signals will probably necessitate use of a beam identifier or "beam ID" which does not exist in LTE. If introduced, the beam ID will be a physical layer concept and a UE will work out a beam ID through special signal such as synchronization signal.
During the time duration T1, it makes sense for UE 11 to compare the measurement results of Cell 1 and Cell 2 to decide whether to trigger related further measurement(s) or prepare a handover. However, it is not reasonable for UE 11 to determine that Cell 3 is a non-suitable cell based on measurement results on Cell 3 during T1, because as FIG. 4 shows the beam of Cell 3 pointing away from UE1 in T1, making Cell 3 hard to detect by UE1.
In fact a more reasonable method is not to permit UE 11 to perform any measurement on Cell 3 during time period T1. In this way UE 11 will reduce power consumption used for measurement and also does not get unreliable measurement data at the same time.
In general the reference signal design for NR could be frequency dependent due to:
(i) Different density/pattern for different numerology
(ii) Different density/pattern in order to save overhead. It could be further time dependent due to 1 different numerology; 2 overhead saving
(iii) Beamforming operation. Moreover, there could be multiple tiers/levels of reference signal for NR, such as cell specific reference signals and beam specific reference signals.
Therefore the measurement configuration message in LTE where the measurement object is carrier frequency dependent, is not suitable for NR and has various shortcomings as follows.
Firstly, the scheme used for LTE cannot reduce measurement complexity when transmission of reference signals is temporarily switched off at a cell. Secondly, after L1 filtering or L3 filtering useful information will be hidden or the result may be a distorted result. For example in FIG. 3, it does not make sense to average the measurement results of either UE 11 or UE 12 over time durations T1 and T2. Thirdly, there is a feasibility issue: in NR a terminal does not always support the system bandwidth; in any case, when carrying out beam level measurement extra information such as beam ID is required, which is not supported by the current message structure.
Therefore the message structure of measurement configuration needs be re-designed for the NR system.

Measurement configuration signalling in 5G


Systems and methods are provided for precharging high-voltage buses. The precharge system comprises an energy source having a first terminal and a second terminal, wherein a first voltage is equal to a potential difference between the first terminal and the second terminal. The precharge system further comprises a bus having a first rail and a second rail, wherein a second voltage is equal to a potential difference between the first rail and the second rail. A first contactor is coupled between the first terminal and the first rail and a second contactor is coupled between the second terminal and the second rail. A controller is coupled to the energy source, the bus, and the contactors. The controller is configured to activate the second contactor, and thereafter activate the first contactor if the magnitude of a difference between the first voltage and the second voltage is less than a threshold tolerance.

In recent years, advances in technology, as well as ever evolving tastes in style, have led to substantial changes in the design of automobiles, particularly the development of electric and hybrid drive systems for improved fuel efficiency. In most hybrid or electric vehicles, high-voltage energy storage systems are utilized to improve efficiency. These high-voltage energy storage systems may capture energy within the powertrain system, for example, by using regenerative braking to convert kinetic energy to electrical energy and storing the electrical energy. Additionally, the high-voltage energy storage systems may store electrical energy supplied from a power supply or charger.
Because of the power capacity of the high-voltage energy storage systems and the desire to retain energy for long periods of time, it is therefore desirable that these high-voltage energy storage systems remain primarily disconnected from other devices and connected as needed. Often, contactors or similar connection mechanisms are used to connect vehicle devices to the high-voltage energy storage systems. However, if the high-voltage energy storage system is connected directly to a device which has an electrical potential that differs from the electrical potential of the energy storage system, a large inrush current will occur. This inrush current may potentially damage electrical components or weld the contactors shut, such that the contactors remain in a permanently closed state.
Accordingly, systems have developed that utilize inrush current limiting to connect the high-voltage energy storage systems with vehicle devices. Most of these systems utilize a precharge resistor connected in series with an additional precharge contactor that is connected to the device. The precharge contactor is closed, allowing a limited current to flow to the device based on the precharge resistor and the RC characteristics of the combined system. Once the voltage supplied to the device reaches a stable level, another contactor is closed and the precharge contactor is opened, thereby removing the precharge resistor from the circuit. These systems often incorporate additional hardware or software to monitor the voltage supplied to the device. Furthermore, there is a delay inherent to these precharge systems, because the RC time constant of these precharge systems governs the time required before connecting the device and transferring high-voltage energy to/from the energy storage system.

Precharging a high-voltage bus using a voltage-regulated power supply


A method for forming a passivation layer is disclosed. In the method, a substrate containing a top surface and a bottom surface opposite to the top surface is first provided, wherein a plurality of conductive pads are disposed on the top surface thereof. Thereafter, a first passivation layer is formed on the top surface of the substrate, wherein the first passivation layer has a characteristic of photoresist. A first exposure/develop step is then performed to form a plurality of first openings in the first passivation layer, wherein the conductive pads are exposed through the first openings. Then, a second passivation layer is formed on the first passivation layer, wherein the second passivation layer has a characteristic of photoresist. A second exposure/develop step is then performed to form a plurality of second openings in the second passivation layer, wherein the conductive pads are exposed through the second openings.

With the development of semiconductor technology, the requirements for packaging integrated circuits have becoming stricter. Currently, most of the high pin-count chips (such as graphic chips and chip sets, etc.) are packaged by a BGA (Ball Grid Array) technique, wherein the BGA technique can be divided into five categories including a PBGA (Plastic BGA) substrate, a CBGA (Ceramic BGA) substrate, a FCBGA (FlipChip BGA) substrate, a TBGA (Tape BGA) substrate, and a CDPBGA (Carity Down PBGA) substrate. The FCBGA technique is to dispose Au or solder bumps on an IC chip for soldering to a printed wiring board (PWB).
For example, referring to FIG. 1, FIG. 1 is a schematic cross-sectional view showing the structure of a conventional solder bump prepared by a film electro-deposition process. Such as shown in FIG. 1, a silicon wafer 100 includes a conductive pad 12, a passivation layer 110, a conductive layer 180 and a solder ball 190. The conductive pad 102, such as an aluminum pad or a copper pad, is used for forming an electrical connection to an external circuit (not shown). The passivation layer 110 is used for providing a semiconductor structure with protection and a planarization surface, wherein the passivation layer 110 allows the surface 102a of the conductive pad 102 to be exposed. The conductive layer 10, such as a UBM (Under Bump Metallurgy Layer) layer formed by sputtering, covers a portion of the passivation layer 110 and the surface 102a of the conductive pad 102. The UBM layer is typically composed of an adhering/diffusion barrier layer 160 and a wetting layer 170, for increasing the adhesion between the solder ball 190 and the conductive pad 102.
Referring to FIG. 2A to FIG. 2D, FIG. 2A to FIG. 2D are schematic cross-sectional views showing the process for making the passivation layer 110 shown in FIG. 1. At first, such as shown in FIG. 2A, a silicon wafer 100 is provided, wherein the silicon wafer 110 has a plurality of conductive pads 102 formed thereon. Then, such as shown in FIG. 2B, a passivation layer 110 is coated on the silicon wafer 100 so as to cover the conductive pads 102, wherein the passivation layer 110 is made of polyimide, and the thickness thereof is about 10 μm. Thereafter, such as shown in FIG. 2C, an exposure/develop step is performed to form a plurality of openings 112 on the passivation layer 110 for exposing the conductive pads 102. Then, such as shown in FIG. 2D, a baking step is performed for curing the passivation layer 110. In the conventional skill, since the passivation layer 110 is formed by only one costing step and covers the entire surface of the silicon wafer 100, a particle 104 (shown in FIG. 2A) if existing on the silicon wafer 100 will easily result in a void 114 (shown in FIG. 2D) formed on the surface of the final passivation layer 110, wherein the existence of the void 114 will easily cause customer complaints and lower the product yield.


A multimode ionization source with improved ionization characteristics that comprises an electrospray ionization source for providing a charged aerosol, an atmospheric pressure chemical ionization (APCI) source including a corona needle having an end positioned downstream from the electrospray ionization source for producing a discharge that further ionizes the charged aerosol, an assist gas inlet positioned adjacent to the corona needle for providing assist gas, the assist gas facilitating ionization of the charged aerosol by the corona discharge, and a conduit having an orifice for receiving ions from the charged aerosol.

Mass spectrometers work by ionizing molecules and then sorting and identifying the molecules based on their mass-to-charge (m/z) ratios. Two key components in this process include the ion source, which generates ions, and the mass analyzer, which sorts the ions. Several different types of ion sources are available for mass spectrometers. Each ion source has particular advantages and is best suited for use with different classes of compounds. Different types of mass analyzers are also used. Each type has advantages and disadvantages depending upon the type of information needed.
Much of the advancement in liquid chromatography/mass spectrometry (LC/MS) over recent years has been in the development of atmospheric pressure ionization (API) sources and techniques that ionize analyte molecules and separate the resulting ions from the mobile phase. Earlier LC/MS systems performed at sub-atmospheric pressures or under partial vacuum, whereas API occurs at atmospheric pressure.
The introduction of API techniques has greatly expanded the number of compounds that can be successfully analyzed using LC/MS. In API techniques, analyte molecules are first ionized at atmospheric pressure. The analyte ions are then spatially and electrostatically separated from neutral molecules. Common API techniques include: electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). Electrospray ionization is the oldest technique and relies in part on chemical effects to generate analyte ions in solution before the analyte reaches the mass spectrometer. The LC eluent is sprayed (nebulized) into a chamber at atmospheric pressure in the presence of a strong electrostatic field and heated drying gas. The electrostatic field charges the LC eluent and the analyte molecules. The heated drying gas causes the solvent in the droplets to evaporate. As the droplets shrink, the charge concentration in the droplets increases. Eventually, the repulsive force between ions with like charges exceeds the cohesive forces and the ions are ejected (desorbed) into the gas phase. The ions are attracted to and pass through a capillary or sampling orifice into the mass analyzer. Some gas-phase reactions, mostly proton transfer and charge exchange, can also occur between the time ions are ejected from the droplets and the time they reach the mass analyzer.
Electrospray is particularly useful for analyzing large biomolecules such as proteins, oligonucleotides, peptides etc. The technique can also be useful for analyzing polar smaller molecules such as benzodiazepines and sulfated conjugates. Other compounds that can be effectively analyzed using electrospray include salts and organic dyes.
Large molecules often acquire more than one charge. Multiple charging provides the advantage of allowing analysis of molecules as large as 150,000 u even though the mass range (or more accurately mass-to-charge range) for a typical LC/MS instrument is around 3000 m/z. When a large molecule acquires many charges, a mathematical process called deconvolution may be used to determine the actual molecular weight of the analyte.
A second common technique performed at atmospheric pressure is atmospheric pressure chemical ionization (APCI). In APCI, the LC eluent is sprayed through a heated vaporizer (typically 250-400° C.) at atmospheric pressure. The heat vaporizes the liquid and the resulting gas phase solvent molecules are ionized by electrons created in a corona discharge. The solvent ions then transfer the charge to the analyte molecules through chemical reactions (chemical ionization). The analyte ions pass through a capillary or sampling orifice into the mass analyzer. APCI has a number of important advantages. The technique is applicable to a wide range of polar and nonpolar molecules. The technique rarely results in multiple charging like electrospray and is, therefore, particularly effective for use with molecules of less than 1500 u. However, APCI may be less useful technique than electrospray in regards to large biomolecules that may be thermally unstable. APCI is used with normal-phase chromatography more often than electrospray because the analytes in this case are usually nonpolar.
Atmospheric pressure photoionization (APPI) for LC/MS is a relatively new technique. As in APCI, a vaporizer converts the LC eluent to the gas phase. A discharge lamp generates photons in a narrow range of ionization energies. The range of energies is carefully chosen to ionize as many analyte molecules as possible while minimizing the ionization of solvent molecules. The resulting ions pass through a capillary or sampling orifice into the mass analyzer. APPI is applicable to many of the same compounds that are typically analyzed by APCI. It shows particular promise in two applications, highly nonpolar compounds and low flow rates (<100 ul/min), where APCI sensitivity is sometimes reduced. In each case, the optimal ionization technique depends to a great extent on the nature of the analyte(s) and the separation conditions.
Each of the techniques described above ionizes molecules through a different mechanism. Unfortunately, none of these techniques are universal sample ion generators. While in some circumstances, the lack of universal ionization could be seen as a potential advantage, it presents a serious disadvantage to the analyst responsible for rapid analysis of samples that are widely divergent. An analyst faced with very limited time and a broad array of numerous samples to analyze is interested in an ion source capable of ionizing as many kinds of samples as possible with as few instrumental adjustments as possible.
Attempts have been made to improve sample ionization coverage by the use of rapid switching between positive and negative ion detection. Rapid positive/negative polarity switching does result in an increase in the percentage of compounds detected by any API technique. However, it does not eliminate the need for more universal API ion generation.
In addition, multimode sources, which include more than one ionization mechanism, have been devised. U.S. Pat. No. 6,646,257 describes a multimode source in which an ESI apparatus is combined with either APCI or APPI. The arrangement of two sources together is effective in that the benefits of each source can be combined, but there remains a need to enhance the efficiency of such multimode sources in order to approach the goal of a "universal" ionization source.

Multimode ion source with improved ionization


A photographic element is disclosed comprising a film support, at least one light-sensitive layer, a highly loaded layer which contains more than 30 volume percent of non-film forming particulate material, and upper and lower aqueous coated adjacent layers which are next to the highly loaded layer, the upper adjacent layer being further from the support and the lower adjacent layer being closer to the support relative to the highly loaded layer, each adjacent layer having a film forming binder content of greater than 70 volume percent, and the lower adjacent layer being at least 1.0 micron thick. In accordance with a preferred embodiment of the invention, an imaging element having excellent adhesion characteristics is obtained in combination with excellent magnetic recording characteristics and photographic transparency where the non-film forming particulate material in the highly loaded layer comprises conductive particles, the layer adjacent to the highly loaded layer which is closer to the support comprises a hydrophilic curl control layer, and the layer adjacent to the highly loaded layer which is further from the support or a layer coated thereover comprises an aqueous coated transparent magnetic recording layer, by virtue of the physical flatness, low granularity, and optical density of the element. Also disclosed is a process for simultaneously applying a plurality of coating compositions comprising an aqueous magnetic recording layer coating composition, an antistatic layer aqueous coating composition, and a curl control layer aqueous coating composition, along with other optional conventional gelatin containing aqueous coated layers, onto a support. The placing of the highly filled antistatic layer between two aqueous coated adjacent layers, which in a preferred embodiment of the invention comprise a magnetic recording layer and a curl control layer or two curl control layers, results in excellent adhesion of the coated layers to the support compared to where the antistatic layer is closest to the support. The mechanical properties of a photographic element containing such a highly filled layer is substantially strengthened when the highly filled layer is sandwiched between the two other aqueous coated layers.

Photographic elements are desirably provided with one or more conductive antistatic layers to prevent undesirable static discharges during manufacture, exposure and processing of the photographic element. Antistats proposed for use in photographic elements include non-film forming particulate materials comprising metal oxides, for example, tin oxide, antimony doped tin oxide, vanadium pentoxide, and metal antimonate particles. Such particulate materials are generally coated in a thin layer at relatively high loading levels relative to any film forming binder in order to provide good antistatic performance while maintaining photographic transparancy. In order to provide good adhesion to a photographic element support, such highly loaded antistatic layers have generally been coated directly over a thin subbing layer on the support. Such antistatic layers are conventionally typically coated on the opposite side ("back-side") of the support relative to the light-sensitive layers of the photographic element. Particular antistatic layer formulations are disclosed in, e.g., U.S. Pat. Nos. 4,203,769, 4,394,441, 4,418,141, 4,495,278, 5,368,995.
It is also known to include in various kinds of imaging elements a transparent magnetic recording layer containing magnetic particles dispersed in a polymeric binder. The inclusion and use of such transparent magnetic recording layers in light-sensitive silver halide photographic elements has been described in, e.g., U.S. Pat. Nos. 3,782,947; 4,279,945; 4,302,523; 5,217,804; 5,229,259; 5,395,743; 5,413,900; 5,427,900; 5,498,512; and others. Such elements are advantageous because images can be recorded by customary photographic processes while information can be recorded simultaneously into or read from the magnetic recording layer by techniques similar to those employed for traditional magnetic recording art.
The transparent magnetic recording layer must be capable of accurate recording and playback of encoded information repeatedly on demand by various devices such as a camera or a photofinishing or printing apparatus. Said layer also must exhibit excellent running, durability (i.e., abrasion and scratch resistance), and magnetic head-cleaning properties without adversely affecting the imaging quality of the photographic elements. However, this goal is extremely difficult to achieve because of the nature and concentration of the magnetic particles required to provide sufficient signal to write and read magnetically stored data and the effect of any noticeable color, haze or grain associated with the magnetic layer on the optical density and granularity of the photographic layers. These goals are particularly difficult to achieve when magnetically recorded information is stored and read from the photographic image area. Further, because of the curl of the photographic element, primarily due to the photographic layers and the core set of the support, the magnetic layer must be held more tightly against the magnetic heads than in conventional magnetic recording in order to maintain planarity at the head-media interface during recording and playback operations. Thus, all of these various characteristics must be considered both independently and cumulatively in order to arrive at a commercially viable photographic element containing a transparent magnetic recording layer that will not have a detrimental effect on the photographic imaging performance and still withstand repeated and numerous read-write operations by a magnetic head.
Problems associated with the formation and discharge of electrostatic charge during the manufacture and utilization of photographic film and paper have been recognized for many years by the photographic industry as discussed above. In films comprising a transparent magnetic recording layer which are designed to be used in automatic cameras, because of the repeated motion of a photographic roll film in and out of a film cassette, there is the added problem of the generation of electrostatic charge by the movement of the film across magnetic heads and by the repeated winding and unwinding operations, especially in a low relative humidity environment. The accumulation of charge on the film surface results in the attraction and adhesion of dust to the film. The presence of dust not only can result in the introduction of physical defects and the degradation of the image quality of the photographic element but also can result in the introduction of noise and the degradation of magnetic recording performance (e.g., S/N ratio, "drop-outs", etc.). This degradation of magnetic recording performance can arise from various sources including signal loss resulting from increased head-media spacing, electrical noise caused by discharge of the static charge by the magnetic head during playback, uneven film transport across the magnetic heads, clogging of the magnetic head gap, and excessive wear of the magnetic heads. Accordingly, the use of a conductive antistatic layer in photographic elements comprising transparent magnetic recording layers is especially important. Typically, in photographic elements of prior art comprising a transparent magnetic recording layer, the antistatic layer is present as a backing layer underlying the magnetic recording layer (see, e.g., U.S. Pat. No. 5,457,013).
It is also frequently desirable to coat one or more curl control layers on the back-side of the support of a photographic film element comprising light-sensitive layers in order to prevent excessive curl in the element upon drying of the coated light-sensitive layers, to ensure the film element remains sufficiently flat in a camera or printer during exposure and printing to optimize focus conditions, as well as to facilitate transport of the film through a camera and processing apparatus. Such back-side curl control layers typically comprise a hydrophilic binder coated from an aqueous formulation, and are of sufficient total thickness upon drying (generally from 1-25 micrometers) to off-set the curl generated by the hydrophilic binder layers on the light-sensitive emulsion layer side of the support to a desired degree. Use of curl control layers is especially important where a transparent magnetic recording layer is included in relatively wide (i.e., wider than 35 mm) roll camera films, such as 120 and 220 medium format films, and sheet films including as x-ray and graphic arts films, as such films are generally more sensitive to curl and the resulting degradation of magnetic recording performance associated with variable head-media spacing. Optimized ratios of the thicknesses of light sensitive layers, magnetic recording layers, and curl control layers comprising hydrophilic colloids in photographic elements for curl control are described, e.g., in copending, commonly assigned U.S. Ser. No. 08/604,272, now U.S. Pat. No. 5,753,426 the disclosure of which is incorporated by reference herein.
Adhesion of a backing layer arrangement comprising a substantial curl control layer package in addition to a magnetic recording layer coated over a highly filled (i.e., low binder), relatively thin antistatic layer on a film support can be problematic where the antistatic layer is coated directly on a support or over a thin primer layer (such as a vinylidene chloride based copolymer layer) as is commonly practiced in the art. It would be advantageous to be able to provide curl control, magnetic recording, and highly filled antistatic layers in a film element which exhibited good adhesion performance. It would further be desirable to provide such a film element wherein such layers are effectively simultaneously coatable from aqueous coating compositions in a single coating pass.

Photographic elements comprising highly loaded particulate material containing layer


The present invention includes compositions and methods of making an activated polymeric nanoparticle for targeted drug delivery that includes a biocompatible polymer and an amphiphilic stabilizing agent non-covalently associated with a spacer compound that includes at least one electrophile that selectively reacts with any nucleophilic on a targeting agent and places the targeting agent on the exterior surface of a biodegradable nanoshell, wherein an active agent is loaded with the nanoshell.

Without limiting the scope of the invention, its background is described in connection with the delivery of active pharmaceutical agents.
One of the greatest problems associated with molecular therapeutics is delivery of the therapeutic agent to the site of action. For the case of anti-cancer agents such as curcumin there is the necessity to keep the dose at minimal levels for the protection of the patient. The reduction in dose however; may not fully treat the disease. Thus, through the direction of a drug delivery device to a specific site of action via the conjugation of various antibodies more advantageous therapeutic regimes can be developed.

Formulation of active agent loaded activated PLGA nanoparticles for targeted cancer nano-therapeutics

University of North Texas Health Science Center at Fort Worth


The present invention relates to recombinant bovine parainfluenza virus (bPIV) cDNA or RNA which may be used to express heterologous gene products in appropriate host cell systems and/or to rescue negative strand RNA recombinant viruses that express, package, and/or present the heterologous gene product. The chimeric viruses and expression products may advantageously be used in vaccine formulations including vaccines against a broad range of pathogens and antigens.

Parainfluenza viral infection results in serious respiratory tract disease in infants and children. (Tao, et al., 1999, Vaccine 17:1100-08). Infectious parainfluenza viral infections account for approximately 20% of all hospitalizations of pediatric patients suffering from respiratory tract infections worldwide. Id. A vaccine has not yet been approved for the prevention of PIV related disease, nor is there an effective antiviral therapy once disease occurs.
PIV is a member of the paramyxovirus genus of the paramyxovirus family. PIV is made up of two structural modules: (1) an internal ribonucleoprotein core, or nucleocapsid, containing the viral genome, and (2) an outer, roughly spherical lipoprotein envelope. Its genome is a single strand of negative sense RNA, approximately 15,456 nucleotides in length, encoding at least eight polypeptides. These proteins include the nucleocapsid structural protein (NP, NC, or N depending on the genera), the phosphoprotein (P), the matrix protein (M), the fusion glycoprotein (F), the hemagglutinin-neuraminidase glycoprotein (HN), the large polymerase protein (L), and the C and D proteins of unknown function. Id.
The parainfluenza nucleocapsid protein (NP, NC, or N) consists of two domains within each protein unit including an amino-terminal domain, comprising about two-thirds of the molecule, which interacts directly with the RNA, and a carboxyl-terminal domain, which lies on the surface of the assembled nucleocapsid. A hinge is thought to exist at the junction of these two domains thereby imparting some flexibility to this protein (see Fields et al. (ed.), 1991, Fundamental Virology, Second Edition, Raven Press, New York, incorporated by reference herein in its entirety). The matrix protein (M), is apparently involved with viral assembly and interacts with both the viral membrane as well as the nucleocapsid proteins. The phosphoprotein (P), which is subject to phosphorylation, is thought to play a regulatory role in transcription, and may also be involved in methylation, phosphorylation and polyadenylation. The fusion glycoprotein (F) interacts with the viral membrane and is first produced as an inactive precursor, then cleaved post-translationally to produce two disulfide linked polypeptides. The active F protein is also involved in penetration of the parainfluenza virion into host cells by facilitating fusion of the viral envelope with the host cell plasma membrane. Id. The glycoprotein, hemagglutinin-neuraminidase (HN), protrudes from the envelope allowing the virus to contain both hemagglutinin and neuraminidase activities. HN is strongly hydrophobic at its amino terminal which functions to anchor the HN protein into the lipid bilayer. Id Finally, the large polymerase protein (L) plays an important role in both transcription and replication. Id.
In one embodiment, the present invention relates to the construction of a cross-species bovine PIV3/human PIV3 chimeric virus vaccine. Bovine parainfluenza virus was first isolated in 1959 from calves showing signs of shipping fever. It has since been isolated from normal cattle, aborted fetuses, and cattle exhibiting signs of respiratory disease (Breker-Klassen, et al., 1996, Can. J. Vet. Res. 60:228-236). See also Shibuta, 1977, Microbiol. Immunol. 23 (7), 617-628. Human and bovine PIV3 share neutralizing epitopes but show distinct antigenic properties. Significant differences exist between the human and bovine viral strains in the HN protein. In fact, while a bovine strain induces some neutralizing antibodies to hPIV infection, a human strain seems to induce a wider spectrum of neutralizing antibodies against human PIV3 (Klippmark, et al., 1990, J. Gen. Vir. 71: 1577-1580). Thus, it is expected that the bPIV3/hPIV3 chimeric virus vaccine of the present invention will also induce a wider spectrum of neutralizing antibodies against hPIV3 infection while remaining attenuated and safe for human use. Other chimeric parainfluenza virus vaccines are also contemplated by the invention.
The replication of all negative-strand RNA viruses, including PIV, is complicated by the absence of cellular machinery required to replicate RNA. Additionally, the negative-strand genome can not be translated directly into protein, but must first be transcribed into a positive-strand (mRNA) copy. Therefore, upon entry into a host cell, the genomic RNA alone cannot synthesize the required RNA-dependent RNA polymerase. The L, P and N proteins must enter the cell along with the genome on infection.
It is hypothesized that most or all of the viral proteins that transcribe PIV mRNA also carry out their replication. The mechanism that regulates the alternative uses (i.e., transcription or replication) of the same complement of proteins has not been clearly identified but appears to involve the abundance of free forms of one or more of the nucleocapsid proteins. Directly following penetration of the virus, transcription is initiated by the L protein using the negative-sense RNA in the nucleocapsid as a template. Viral RNA synthesis is regulated such that it produces monocistronic mRNAs during transcription.
Following transcription, virus genome replication is the second essential event in infection by negative-strand RNA viruses. As with other negative-strand RNA viruses, virus genome replication in PIV is mediated by virus-specified proteins. The first products of replicative RNA synthesis are complementary copies (i.e., plus-polarity) of PIV genome RNA (cRNA). These plus-stranded copies (anti-genomes) differ from the plus-strand mRNA transcripts in the structure of their termini. Unlike the mRNA transcripts, the anti-genomic cRNAs are not capped and methylated at the 5′ termini, and are not truncated and polyadenylated at the 3′ termini. The cRNAs are coterminal with their negative strand templates and contain all the genetic information in the complementary form. The cRNAs serve as templates for the synthesis of PIV negative-strand viral genomes (vRNAs).
Both the bPIV negative strand genomes (vRNAs) and antigenomes (cRNAs) are encapsidated by nucleocapsid proteins; the only unencapsidated RNA species are virus mRNAs. For bPIV, the cytoplasm is the site of virus RNA replication, just as it is the site for transcription. Assembly of the viral components appears to take place at the host cell plasma membrane and mature virus is released by budding.

This patent is subject to a terminal disclaimer.

Recombinant parainfluenza virus expression systems and vaccines


A method system, interface and server for establishing a communications call by selecting a B party (6) using an interactive device (16) connected to a public network (10,12), sending called address data for the B party (6) and calling address data for an A party (4) to a communications platform (18) of the public network (10,12), and establishing a call between the A and B parties (4,6) over the public network (10,12) using the communications platform (18) and the called and calling address data. The called address data can be accessed from the public network, and may reside on a server of a messaging network, such as the Internet.

Currently to establish a public telecommunications call requires an originating party to know the telephone number of the destination and to take steps to either manually dial the number or to cause the number to be accessed from a database maintained by the originating party and dialed. If the originating party does not know the number of the destination then service personnel of a carrier can be contacted to obtain the number and if desired connect the originating party and destination party, hereinafter referred to as the A and B party, respectively.
The B party's number can also be determined by consulting a public directory which may be in print or electronic form. A call with the B party can then be established by dialing the number obtained.
As information concerning the B party's number is known by a telecommunications carrier a method and system is desired to enable that information to be used automatically, on request, to establish a call between the A party and the B party without the caller having to dial the number.

Method of establishing a communications call


A system and method of tracking a flexible elongate instrument within a patient is disclosed herein. The system is configured to obtain remote localization measurement data of the flexible elongate instrument and obtain elongation measurement data of the flexible elongate instrument. This data is combined and transformed to a coordinate reference frame to produce a localization of the flexible elongate instrument that is more accurate than the remote localization measurements or elongation measurement data alone. The combined localization is then provided to a localization consumer.

Currently known minimally invasive procedures for diagnosis and treatment of medical conditions use shapeable instruments, such as steerable devices, flexible catheters or more rigid arms or shafts, to approach and address various tissue structures within the body. For various reasons, it is highly valuable to be able to determine the 3-dimensional spatial position of portions of such shapeable instruments relative to other structures, such as the operating table, other instruments, or pertinent anatomical tissue structures. Such information can be used for a variety of reasons, including, but not limited to: improve device control; to improve mapping of the region; to adapt control system parameters (whether kinematic and/or solid mechanic parameters); to estimate, plan and/or control reaction forces of the device upon the anatomy; and/or to even monitor the system characteristics for determination of mechanical problems. Alternatively, or in combination, shape information can be useful to simply visualize the tool with respect to the anatomy or other regions whether real or virtual.
However, a primary difficulty in using flexible devices is the inability to determine the location and/or shape of the flexible device within the body. In non-flexible, discrete devices, such detection and monitoring tasks may be accomplished with encoders or other techniques (such as visual tracking of a portion of the device external to the body) that utilized the rigid nature of linkages. Such conventional techniques are not practical with flexible device as such devices contain non-rigid linkages or too many individual linkages to effectively determine location and/or shape of the flexible device.
There remains a need to apply the information gained by the localization techniques to determine the location, orientation and shape of a flexible device and applying this information to produce improved device control or improved modeling when directing a robotic or similar device. There also remains a need to apply such controls to medical procedures and equipment.

Flexible instrument localization from both remote and elongation sensors


An improved per-tone FEQ method with a noise reduction technique using periodic training pilot tones increases the throughput for long-reached modems. This method can reduce the noise effects in estimating FEQ equalizer coefficients. Each per-tone FEQ can be estimated by using the periodic training signals and an averaging technique to remove noise from each sub-channel (EQN. VI). After solving the system equations (EQN. IV), per-tone equalization coefficients of the FEQ equalizer for each group can be combined to obtain the optimized results in the form of the Toeplitz matrix (EQN. V). Each element within the Toeplitz matrix can be derived from the averaging technique used to remove noise from each sub-channel (EQN. VI). To demodulate a signal with the Toeplitz matrix, an inverse of every element in a row of the Toeplitz matrix is taken and multiplied by the sending signal which creates an N Log N matrix.

In modem telecommunications, unshielded twisted pairs (UTP) are used on a massive scale. The lower price of this transmission system and already established infrastructure currently are the main advantages of phone lines over optical lines. In comparison with single carrier modulation, the benefits of multicarrier modulation (MCM) can be explained as that the capacity of a MCM for a band limited system is always greater than the capacity of a single carrier system if channel SNR is not constant. Among MCM systems for wired communications, only Discrete Multitone (DMT) is currently deployed. Another MCM technique of interest is Filtered Multitone (FMT) system but will not be discussed further.
DMT modulation has become an important transmission method for asymmetric digital subscriber lines (ADSLs) which provides a high bit rate downstream channel and a lower bit rate upstream channel over twisted pair copper wire. DMT divides the available bandwidth into parallel subchannels or tones. Bits and power are allocated to individual subchannels or tones of an Inverse Fast Fourier Transform (IFFT)/Fast Fourier Transform (FFT) to maximize the data rate for a fixed margin or to maximize the margin for a fixed data rate. The process of allocating bits and power to individual subchannels is referred to as bit loading.
In other words, an incoming serial bitstream is divided into parallel streams which are used to Quadrature Amplitude Modulation (QAM)-modulate the different tones. After modulation with an IFFT, a cyclic prefix is added to each symbol being transmitted. The use of a cyclic prefix (pre-pending the tail of a signal after the IFFT to the block to be transmitted) allows for simplified equalization at the receiver with equalizers if the channel memory is not larger than the length of the cyclic prefix. In this case, equalization simply reduces to multiplication by a complex number on a subchannel by subchannel basis to remove the effects of the channel. Effects of the channel which can distort a communications signal can include, but are not limited to, noise in general, signal loss or attenuation, and phase noise. A channel can include, but is not limited to, a twisted wire pair, a coaxial cable, a bundle of cables, optical waveguides, and wireless mediums such as RF communications in the form of over-the-air transmissions and satellite transmissions.
Equalization that includes multiplication by a complex number on a subchannel by subchannel basis can be achieved with a combination of an IFFT, channel, and FFT that results in a diagonal matrix relating to the input block of data that is transmitted to the received block of data, with the channel response as the elements of the diagonal. In other words, if the cyclic prefix is longer than the channel impulse response, demodulation of a signal can be implemented with a FFT, followed by a complex 1-Tap Frequency Domain Equalizer (FEQ) per tone to compensate for the channel amplitude and phase effects.
Equalizers are devices generally used in receivers to compensate for the effects on a channel that can be established between a receiver and a transmitter. Equalizers compensate for these effects mathematically. Equalizers can operate in the time domain or in the frequency domain. Time domain equalizers (TEQs) can shorten the impulse response of a channel and they can partially bandpass an incoming signal as well as filter out-of-band noise power. TEQs are generally adaptive in nature and its coefficients are usually trained during initialization. On the other hand, FEQs can compensate amplitude attenuation and phase shift in frequency domain of received signals due to the effect of a band-limited channel.
A long cyclic prefix, however, results in a large overhead with respect to data rate. A conventional solution for this problem is to insert a real T-tap time-domain equalizer (TEQ) before demodulation, to shorten the channel impulse response. Imperfectly shortened channel impulse responses can yield to intersymbol interference (ISI) between two successive symbols and intercarrier interference (ISI) between different carriers.
Conventional algorithms have been developed to initialize the TEQ. The TEQ-initialization can compute a TEQ such that a cascade of channel impulse response and TEQ forms a finite impulse response (FIR) channel with a length shorter than the cyclic prefix. This criterion leads to use of a minimum mean square error (MMSE) technique for demodulation. Further details of MSME techniques and DMT are generally described in a printed publication, "Per Tone Equalization for DMT-Based Systems," authored by Van Acker et al. for the IEE Transactions on Communications, Volume 49, No. 1, Jan. 2001, the entire contents of which are hereby incorporated by reference.
Back to MCM systems in general, many conventional MCM systems operating on long loops have very limited data throughput. The data throughput is limited by severe attenuation and thermal noise even when water-filling algorithms are used. For long loops beyond 18 Kft Far End Crosstalk (FEXT) is the only significant crosstalk and the total "noise" is dominated by Additive White Gaussian Noise (AWGN), which is typically −140 dBm/Hz. Reducing the thermal noise, accurately estimating the equalizer to cancel the channel distortion, and increasing the throughput for these long loops are severe challenges.
To increase the data rate for a long-reach modem, one of the major problems is using ISI cancellation. By using the averaging techniques for the noise reduction, ISI cancellation can be accomplished. Further, in order to estimate the equalization coefficients accurately, thermal noise should be removed from the training signal. One of the methods to combat ISI is the MMSE equalization, which is based on the minimization of a cost function. In MMSE, although the equalizer coefficients are calculated to minimize the MMSE error, the accuracy of the equalizer is still compromised due to thermal noise. As the length of the channel increases, the system matrix may become ill conditioned. The inversion of a system matrix can become mathematically intricate and additionally if the matrix has nulls, it becomes non-invertible. Various MMSE equalizers based on similar schemes with different constrains suffer from the same problems.
In view of the foregoing, there is a need in the art for initializing a modem in a mathematically less complex or more simple manner and in a shorter period of time. There is also a need in the art for increasing the data rate for long distance reach over existing telephone lines.

Method for initialization of per tone frequency domain equalizer (FEQ) through noise reduction for multi-tone based modems


A self-sealing catheter and guidewire introducer has a self-sealing gasket adapted to effect a seal when a catheter or guidewire extends through the gasket as well as when neither extends through the gasket.

U.S. Pat. No. 4,424,833 (Spector et al.) discloses a catheter introducer having a self-sealing gasket adapted to maintain a seal and prevent back bleeding both when the catheter is in place through the introducer as well as when the catheter is removed. The Spector et al. device also includes a side entry port through which liquids may be introduced or through which the device may be aspirated. The device is effective to provide a self-sealing gasket that maintains its seal over a relatively wide range of pressures to include not only the normal positive pressure of the patient's blood but also the reduced pressure which results from aspirations through the side port. The device also displays the desirable feature that its self-sealing function is achieved without unduly inhibiting axial and rotary movement of the catheter as it passes through the seal.
Although the foregoing device maintains an effective seal with a catheter passing through it as well as when the catheter is not present, it is somewhat limited in the range of diameters of devices that can be passed through it while maintaining a seal. In particular, guidewires, which typically are used in association with catheters, are of significantly smaller diameter than the catheters and when passed through the gasket, do not maintain an effective seal with the gasket. The guidewires, however, are sufficiently large to break the seal which permits blood to leak out of the proximal end of the device. Therefore, it would be desirable to provide a device having a self-sealing structure that is effective to provide a seal when a catheter as well as when a guidewire extends through the introducer. Moreover, such a device also should be effective to maintain the seal when neither the guidewire nor catheter are in place as well as during aspiration and over a relatively wide range of pressures. Further, such a device should not unduly inhibit axial as well as rotary movement of the catheter or the guidewire. It is among the general objects of the invention to provide such an improved gasketed introducer.

Self-sealing guidewire and catheter introducer


An electrically operated valve assembly having a plastic body with a solenoid coil attached for moving an armature valve member for effecting flow from the vale inlet to outlet. In one embodiment the armature is a pilot valve slidably movable in a guide over which the solenoid is received. A spring loaded check valve in the guide releases over pressure within the valving chamber. In another embodiment a spring loaded check valve in the body inlet passage releases over pressure to a bypass passage to the outlet. In a third embodiment a slug having a spring loaded poppet relief valve is welded over an opening in the inlet passage at generally right angles to the inlet fitting to provide direct relief of over pressure in the inlet.

The present invention relates to electrically operated valves such as solenoid operated valves employed for controlling water inlet to household appliances such as washing machines, dishwashers, and icemakers for refrigerators. Solenoid operated water inlet valves for household appliances typically utilize a plastic valve body and movable diaphragm type valving and are connected to a water supply by means of a compression type tube fitting in the case of small flow valves. Where relatively large flow is required, such as for washing machines, the valves typically of the pilot operated variety, and employ an electric coil disposed over a guide member with a movable armature therein for opening the pilot valve which creates a pressure differential across the diaphragm for effecting opening of the main valves. The water inlet valves of the aforesaid type may be connected directly to the household plumbing; and, the plumbing may be recessed in a wall of the building exposed to outside air temperatures. Where the plumbing is directed through an outside wall, problems are often encountered with freezing of the plumbing within the wall in regions insufficiently insulated to prevent sub-freezing temperatures from occurring in the plumbing during periods of non use. When ice forms in a localized region of the plumbing, the expansion caused during ice formation creates pressures in the plumbing which are substantially greater and often an order of magnitude greater than the normal pressures experienced in the water supply. These high pressures generated by ice formation in the household plumbing may cause bursting of the plastic bodied water inlet valve, which may be undetected at the time the burst occurs. Subsequently, upon the thawing of ice in the plumbing, flooding occurs through the appliance due to water flow through the burst in the inlet valve.
Thus it has been desired to provide a way or means of providing in a convenient, low-cost manner, high pressure relief for plastic bodied, electrically operated appliance water inlet valves to prevent rupture of the valves upon experiencing extraordinarily high pressures at the inlet such as the pressure experienced on the occasion of freezing in the plumbing structure to which the valve is connected for household use.


There is provided a method for providing hearing assistance to a user (101), comprising capturing audio signals by a microphone arrangement (26) and transmitting the audio signals by a transmission unit (102) via a wireless audio link (107) to a receiver unit (103), analyzing the audio signals by a classification unit (134) prior to being transmitted in order to determine a present auditory scene category from a plurality of auditory scene categories, setting by a gain control unit (126) located in the receiver unit (103) the gain applied to the audio signals according to the present auditory scene category determined by the classification unit, and stimulating the user's hearing by stimulating means (136) worn at or in a user's ear according to the audio signals from the gain control unit (126).

1. Field of the Invention
The present invention relates to a method for providing hearing assistance to a user; it also relates to a corresponding system. In particular, the invention relates to a system comprising a transmission unit comprising a microphone arrangement for capturing audio signals, a receiver unit, and means for stimulating the hearing of the user wearing the receiver unit, with the audio signals being transmitted via a wireless audio link from the transmission unit to the receiver unit.
2. Description of Related Art
Usually in such systems the wireless audio link is an FM radio link. The benefit of such systems is that sound captured by a remote microphone at the transmission unit can be presented at a high sound pressure level to the hearing of the user wearing the receiver unit at his ear(s).
According to one typical application of such wireless audio systems, the stimulating means is a loudspeaker which is part of the receiver unit or is connected thereto. Such systems are particularly helpful for being used in teaching normal-hearing children suffering from auditory processing disorders (APD), wherein the teacher's voice is captured by the microphone of the transmission unit, and the corresponding audio signals are transmitted to and are reproduced by the receiver unit worn by the child, so that the teacher's voice can be heard by the child at an enhanced level, in particular with respect to the background noise level prevailing in the classroom. It is well known that presentation of the teacher's voice at such enhanced level supports the child in listening to the teacher.
Usually in such systems the audio signals received by the receiver are amplified at a given constant gain for being reproduced by the output transducer. FIG. 5 shows an example of a block diagram of such a conventional receiver unit 103 comprising an antenna 123, an FM radio receiver 124, an amplifier 138 operating at constant gain, a power audio amplifier 137 for a loudspeaker 136, and a manual volume control 135 acting on the power amplifier 137. Such receiver unit has as a drawback that due to the constant gain the audio signals received from the remote microphone are amplified irrespective of whether they are desired by the user (e.g. if the teacher is silent there is no benefit to the user by receiving audio signals from the remote microphone, which then may consist primarily of noise).
According to another typical application of wireless audio systems the receiver unit is connected to or integrated into a hearing instrument, such as a hearing aid. The benefit of such systems is that the microphone of the hearing instrument can be supplemented or replaced by the remote microphone which produces audio signals which are transmitted wirelessly to the FM receiver and thus to the hearing instrument. In particular, FM systems have been standard equipment for children with hearing loss in educational settings for many years. Their merit lies in the fact that a microphone placed a few inches from the mouth of a person speaking receives speech at a much higher level than one placed several feet away. This increase in speech level corresponds to an increase in signal-to-noise ratio (SNR) due to the direct wireless connection to the listener's amplification system. The resulting improvements of signal level and SNR in the listener's ear are recognized as the primary benefits of FM radio systems, as hearing-impaired individuals are at a significant disadvantage when processing signals with a poor acoustical SNR.
Most FM systems in use today provide two or three different operating modes. The choices are to get the sound from: (1) the hearing instrument microphone alone, (2) the FM microphone alone, or (3) a combination of FM and hearing instrument microphones together.
Usually, most of the time the FM system is used in mode (3), i.e. the FM plus hearing instrument combination (often labeled "FM+M" or "FM+ENV" mode). This operating mode allows the listener to perceive the speaker's voice from the remote microphone with a good SNR while the integrated hearing instrument microphone allows to listener to also hear environmental sounds. This allows the user/listener to hear and monitor his own voice, as well as voices of other people or environmental noise, as long as the loudness balance between the FM signal and the signal coining from the hearing instrument microphone is properly adjusted. The so-called "FM advantage" measures the relative loudness of signals when both the FM signal and the hearing instrument microphone are active at the same time. As defined by the ASHA (American Speech-Language-Hearing Association 2002), FM advantage compares the levels of the FM signal and the local microphone signal when the speaker and the user of an FM system are spaced by a distance of two meters. In this example, the voice of the speaker will travel 30 cm to the input of the FM microphone at a level of approximately 80 dB-SPL, whereas only about 65 dB-SPL will remain of this original signal after traveling the 2 m distance to the microphone in the hearing instrument. The ASHA guidelines recommend that the FM signal should have a level 10 dB higher than the level of the hearing instrument's microphone signal at the output of the user's hearing instrument.
When following the ASHA guidelines (or any similar recommendation), the relative gain, i.e. the ratio of the gain applied to the audio signals produced by the FM microphone and the gain applied to the audio signals produced by the hearing instrument microphone, has to be set to a fixed value in order to achieve e.g. the recommended FM advantage of 10 dB under the above-mentioned specific conditions. Accordingly, heretofore—depending on the type of hearing instrument used—the audio output of the FM receiver has been adjusted in such a way that the desired FM advantage is either fixed or programmable by a professional, so that during use of the system the FM advantage—and hence the gain ratio—is constant in the FM+M mode of the FM receiver.
EP 0 563 194 B1 relates to a hearing system comprising a remote microphone/transmitter unit, a receiver unit worn at the user's body and a hearing aid. There is radio link between the remote unit and the receiver unit, and there is an inductive link between the receiver unit and the hearing aid. The remote unit and the receiver unit each comprise a microphone, with the audio signals of theses two microphones being mixed in a mixer. A variable threshold noise-gate or voice-operated circuit may be interposed between the microphone of the receiver unit and the mixer, which circuit is primarily to be used if the remote unit is in a line-input mode, i.e. the microphone of the receiver then is not used.
WO 97/21325 A1 relates to a hearing system comprising a remote unit with a microphone and an FM transmitter and an FM receiver connected to a hearing aid equipped with a microphone. The hearing aid can be operated in three modes, i.e. "hearing aid only", "FM only" or "FM+M". In the FM+M mode the maximum loudness of the hearing aid microphone audio signal is reduced by a fixed value between 1 and 10 dB below the maximum loudness of the FM microphone audio signal, for example by 4 dB. Both the FM microphone and the hearing aid microphone may be provided with an automatic gain control (AGC) unit.
WO 2004/100607 A1 relates to a hearing system comprising a remote microphone, an FM transmitter and left-and right-ear hearing aids, each connected with an FM receiver. Each hearing aid is equipped with a microphone, with the audio signals from remote microphone and the respective hearing aid microphone being mixed in the hearing aid. One of the hearing aids may be provided with a digital signal processor which is capable of analyzing and detecting the presence of speech and noise in the input audio signal from the FM receiver and which activates a controlled inverter if the detected noise level exceeds a predetermined limit when compared to the detected level, so that in one of the two hearing aids the audio signal from the remote microphone is phase-inverted in order to improve the SNR.
WO 02/30153 A1 relates to a hearing system comprising an FM receiver connected to a digital hearing aid, with the FM receiver comprising a digital output interface in order to increase the flexibility in signal treatment compared to the usual audio input parallel to the hearing aid microphone, whereby the signal level can easily be individually adjusted to fit the microphone input and, if needed, different frequency characteristics can be applied. However, is not mentioned how such input adjustment can be done.
Contemporary digital hearing aids are capable of permanently performing a classification of the present auditory scene captured by the hearing aid microphones in order to select the hearing aid operation mode which is most appropriate for the determined present auditory scene. Examples for such hearing aids with auditory scene analyses can be found in US2002/0037087, US2002/0090098, CA 2 439 427 A1 and US2002/0150264.
Usually FM or inductive receivers are equipped with a squelch function by which the audio signal in the receiver is muted if the level of the demodulated audio signal is too low in order to avoid user's perception of excessive noise due a too low sound pressure level at the remote microphone or due to a large distance between the transmission unit and the receiver unit exceeding the reach of the FM link, see for example U.S. Pat. No. 5,734,976 and EP 1 619 926 A1
It is an object of the invention to provide for a method and a system for providing hearing assistance to a user, wherein a remote microphone arrangement coupled by a wireless audio link to a receiver unit which provides the audio signals to means for stimulating the hearing of the user wearing the receiver unit is used and wherein the listening comfort, and in particular the signal-to-noise-ratio (SNR), of the audio signals from the microphone arrangement should be optimized at any time.
It is a further object of the invention to provide for a method and a system for providing hearing assistance to a user, wherein a remote first microphone arrangement coupled by a wireless audio link to a hearing instrument and a second microphone arrangement connected to or integrated into the hearing instrument are used and wherein the SNR of the audio signals from at least one of the first and second microphone arrangement should be optimized at any time.
According to the invention, these objects achieved by a method as defined in claim 1 and a system as defined in claim 55, and by a method as defined in claim 33 and a system as defined in claim 57, respectively.

Method and system for providing hearing assistance to a user


A method for fabricating a nitride semiconductor light emitting device, and a nitride semiconductor light emitting device fabricated thereby are provided. The method includes: forming a first conductive nitride semiconductor layer on a substrate; forming an active layer on the first conductive nitride semiconductor layer; forming a second conductive nitride semiconductor layer on the active layer; and lowering a temperature while adding oxygen to the result by performing a thermal process.

1. Field of the Invention
The present invention relates to a method of fabricating a nitride semiconductor light emitting device, and a nitride semiconductor light emitting device fabricated thereby.
2. Description of the Related Art
Nitride semiconductors have been receiving attention as a raw material of blue light emitting diode or blue laser diode.
Such a nitride semiconductor light emitting device is grown on a sapphire substrate or a SiC substrate. Then, a polycrystalline thin film AlyGa1-yN is grown on a sapphire substrate or a SiC substrate at a low temperature as a buffer layer.
Afterward, an n-GaN layer is formed on the buffer layer by growing an undoped GaN layer and a silicon doped n-GaN layer, or a composite structure thereof at a high temperature. Then, a magnesium Mg doped p-GaN layer is formed thereon so as to fabricate a nitride semiconductor light emitting device. A light emitting layer, which is a single quantum well structure or a multi quantum well structure, is formed as a sandwich structure between the n-GaN layer and the p-GaN layer.
The p-GaN layer is formed by doping a GaN layer with Mg atoms in crystal growth. During crystal growth, Mg atoms injected as a doping source are placed at Ga locations to form the p-GaN layer. However, Mg atoms react with hydrogen gas from a carrier gas or a source. As a result, Mg—H complex is formed thereby. Therefore, the Mg—H complex may become a high resistor, for example, about 10 MΩ.
Therefore, a post-activation process is required after forming a p-n junction light emitting device to place the Mg atoms to Ga locations by disjoining Mg—H complex. However, the amount of carrier for light emitting in the activation process is about 2.25×1017/cm3 in the light emitting device. Therefore, it is difficult to form a resistive contact.
Therefore, there are many researches in progress for overcoming the shortcomings arisen by Mg—H complex.

Fabrication method of nitride semiconductor light emitting device and nitride semiconductor light emitting device thereby


Disclosed herein are systems, methods, and computer-readable storage media for identifying and remediating risky source files. An example system configured to practice the method can gather data describing each file in a source code repository, and generate, using a weighted algorithm based on empirical relationships between the data and customer-found defects, a risk score for each file in the source code repository, wherein the weighted algorithm prioritizes factors based on predictiveness of defects. Then the system can generate a list of files having risk scores above a threshold, and make risk-mitigation recommendations based on the risk scores. A file can include a single file or a collection of files such as a module. The system can identify, for each file in the list of files having risk scores above the threshold, a respective risk type, and make the risk-mitigation recommendation for each file based on the respective risk type.

1. Technical Field
The present disclosure relates to software development and more specifically to identifying high risk areas of code and proposing actions to mitigate or reduce the risk in those high risk areas.
2. Introduction
Software development is a complex process. As software projects expand, the teams working on the software projects also expand, and often include globally distributed teams of developers. Further, the source code itself is often divided, so that often very few developers have a complete picture of the entire software package under development. As the development of software products frequently transitions among globally distributed teams, the knowledge about the source code, design decisions, original requirements, and the history of troublesome areas can be lost or forgotten. A new team taking over development of a software project faces tremendous challenges to regain that knowledge. Loss of such knowledge is one source of introducing defects into software projects. Software defects can come from many other sources, as well.
Empirical data show that approximately 1% of project source code files are involved in more than 60% of customer reported defects. Because risk is omnipresent in software development, many development strategies are explicitly or implicitly designed to minimize risk. Existing solutions to mitigate risk do not correctly identify files with the highest risk. For example, static analysis warnings have only a weak relationship to customer reported software defects. Defect prediction algorithms can predict defects within individual files in a limited fashion, but do not operate on groups of files that account for the most defects. Each of these existing approaches has deficiencies in identifying and reducing risk in software development projects.

System and method for prioritizing and remediating defect risk in source code