bluuebunny/crossref_metadata_2025 huggingface dataset:
Child growth monitoring and promotion practice and associated factors among health care workers at public health facilities in south Wollo Zone, Northeast Ethiopia: a facility-based cross-sectional study
Authors: Kebede Getabalew Getachew , Dawed Yeshimebet Ali , Seid Kemal Ahmed
Published: September 2022

Background

Growth monitoring and promotion (GMP) is one of the health care priorities to assess and follow the growth pattern of children under 2 years old. Appropriate GMP services enable health care workers to control growth faltering early and child mortality. However, there is limited information showing the practice and associated factors of GMP service among health care workers in Ethiopia. Therefore, this study aimed to assess the practice and identify associated factors of GMP service among health care workers at public health facilities of the South Wollo Zone, northeast Ethiopia.

Methods

A facility-based cross-sectional study was conducted on 397 randomly selected health care workers in the South Wollo Zone, northeast Ethiopia, from May 25 to July 7, 2020. A pretested self-administered questionnaire and in-depth interview were used to collect the quantitative and qualitative data, respectively. Quantitative data were entered using Epi data Version 3.1 and exported to statistical software for social sciences (SPSS) version 20.0 software for further analysis. Binary logistic regression analyses were used to identify factors associated with GMP practice. Statistical tests at a P value < 0.05 with a 95% confidence interval were taken as a cutoff point to determine the statistical significance. Qualitative data were analyzed by using thematic analysis.

Results

In this study, the proportion of GMP practice among health care workers was 58.4% (95% CI: 54.0–63.0). Being a holder of first degree (AOR = 2.25; 95% CI: 1.01, 5.05), being a holder of a diploma (AOR = 3.52; 95% CI: 2.04, 6.09), work experience with GMP (AOR = 3.13; 95% CI: 1.58, 6.20), receiving GMP training (AOR = 4.83; 95% CI: 2.89, 8.06), availability of GMP equipment (AOR = 2.75; 95% CI: 1.64, 4.58) and having a positive attitude toward GMP (AOR = 3.70; 95% CI: 2.23, 6.17) were factors significantly associated with GMP practice.

Conclusions and recommendations

The proportion of GMP practice among health care workers was still low. Educational level, work experience with GMP, GMP training, GMP equipment and attitude toward GMP were positively associated with GMP practice. Availability of GMP equipment brings positive attitudes toward GMP, and GMP training for health care workers with less experience should be strengthened to improve GMP practice.
Operational flexibility for multi-purpose usage of pooled battery storage systems
Authors: Tiemann Paul Hendrik , Nebel-Wenner Marvin , Holly Stefanie , Frost Emilie , Jimenez Martinez Adrian , Nieße Astrid
Published: September 2022

The multi-purpose usage of battery energy storage systems (BESSs) increases the exploitation of their flexibility potential. This can be further enhanced when a large number of small BESSs are combined into a swarm and marketed collectively by an aggregator. To this end, a unified representation of remaining flexibility for each BESS is needed that meets the requirements of both, a multi-purpose usage and a distributed swarm design. In this work, we present a compact model which we call abstract multi-purpose-limited flexibility (Amplify). It can be used by an aggregator to determine how much flexibility remains after accepting obligations and includes an integrated detection of conflicts in the planned schedule of a BESS. It is shown that the model is quickly computable and does not need much data volume during transmission.
Earnings surprise and share price of firms in Nigeria
Authors: Ogbaisi Sebastine Abhus , Dabor Eyesan Leslie , Omokhudu Okun Omokhoje
Published: September 2022

This study examines earnings surprise and share price of firms in Nigeria. It sought to evaluate the impact of earnings surprise in predicting share price of firms. The paper employed the Ohlson valuation model and variants of the model to ascertain the impact of earnings surprise on share price. The sample consisted of 76 listed firms over the period 2010–2020. The study reveals that earnings surprise has a negative insignificant impact on share price. The study further reveals that with the interaction of earnings surprise with the bottom line metrics of book value per share and earnings per share, earnings surprise also has a negative insignificant impact on share price of firms, respectively. The paper provides fact that earnings surprise interacts with book value per share and earnings per share in determining share price. This paper also presents evidence to the fact that investors are not just concerned with the magnitude of book value per share and earnings per share but are also concerned with the quality of the earnings in terms of its surprise. This paper further presents evidence to the fact that investors do not consider magnitude and surprise of earnings in isolation. Rather, the decision is influenced by the fusion of the magnitude and the surprise of the metric.
Epidemiology of posttraumatic stress disorder: A prospective cohort study based on multiple nationwide Swedish registers of 4.6 million people
Authors: Rahman Syed , Zammit Stanley , Dalman Christina , Hollander Anna-Clara
Published: September 2022

Background

Experiencing exceptionally threatening or horrifying traumas can lead to posttraumatic stress disorder (PTSD). Increasing political unrest/war/natural disasters worldwide could cause more traumatic events and change the population burden of PTSD. Most PTSD research is based on surveys, prone to selection/recall biases with inconsistent results. The aim was therefore, to use register-based data to identify the occurrence of PTSD and contributing factors in the Swedish general population.

Methods

This register-based cohort study used survival analysis. Individuals born between 1960–1995, aged ≥15 years, registered and living in Sweden, not emigrating, anytime between 1990–2015, not receiving specialized care for PTSD before 2006 were included (N = 4,673,764), and followed from their 15th/16th birth date until first PTSD diagnosis between 2006–2016 or study endpoint (31-December-2016). PTSD cases (ICD-10: F43.1) were identified from the national patient register. Mean follow-up time was 18.8 years.

Results

Between 2006–2016, the incidence of specialized healthcare utilization for PTSD nearly doubled, and 0.7% of the study population received such care. The highest risk was observed for refugees [aHR 8.18; 95% CI:7.85–8.51] and for those with depressive disorder [aHR 4.51; 95% CI:3.95–5.14]. Higher PTSD risk was associated with female sex, older age, low education, single parenthood, low household income, urbanicity, and being born to a foreign-born parent.

Conclusions

PTSD is more common among refugee migrants, individuals with psychiatric disorders, and the socioeconomically disadvantaged. It is important that provision of services for PTSD are made available, particularly to these higher risk, and often hard-to-reach groups.
Reduced Sensitivity to Thyroid Hormones Is Associated With High Remnant Cholesterol Levels in Chinese Euthyroid Adults
Authors: Sun Honglin , Zhu Wei , Liu Jia , An Yu , Wang Ying , Wang Guang
Published: September 2022

Context

It remains unclear whether the thyroid system could regulate the atherogenic remnant cholesterol (RC) levels in euthyroid status.

Objective

We aimed to investigate the relationship between sensitivity to thyroid hormones and RC levels in Chinese euthyroid population.

Methods

This study included 18 766 euthyroid adults. High RC levels were defined as the upper quartile of RC levels. The thyroid hormone sensitivity indices, including thyroid feedback quantile-based index (TFQI), thyroid-stimulating hormone index (TSHI), thyrotrophic thyroxine resistance index (TT4RI), and free triiodothyronine to free thyroxine (FT3/FT4) ratio were calculated. Linear and binary logistic regression analysis were applied to determine the associations between those composite indices with RC levels by genders.

Results

Both females and males with high RC levels exhibited co-existing higher TSH and FT4 levels. Linear regression analysis revealed that TFQI, TSHI, and TT4RI were positively, while FT3/FT4 ratio levels were negatively associated with serum RC levels. The odds ratios (ORs) (95% CI) for high RC levels were increased with rising TFQI quartiles (Q) [females: Q3 1.41 (1.22-1.63), Q4 1.61 (1.39-1.86); males: Q3 1.25 (1.09-1.45), Q4 1.38 (1.19-1.59), all P for trend < 0.001] after full adjustment, with Q1 as the reference. TSHI and TT4RI yielded similar results. By contrast, the ORs (95% CI) for high RC levels were decreased with increasing FT3/FT4 ratio quartiles in both genders (P for trend < 0.001).

Conclusion

In euthyroid adults, reduced sensitivity to thyroid hormones was associated with high RC levels. Our results suggested an additive cardiometabolic risk of euthyroid population with thyroid hormones insensitivity.
Three-Year Observation of Glucose Metabolism After Pancreaticoduodenectomy: A Single-Center Prospective Study in Japan
Authors: Niwano Fumimaru , Babaya Naru , Hiromine Yoshihisa , Matsumoto Ippei , Kamei Keiko , Taketomo Yasunori , Yoshida Sawa , Takeyama Yoshifumi , Noso Shinsuke , Ikegami Hiroshi
Published: September 2022

Context

The glucose tolerance of patients changes considerably from before to after pancreaticoduodenectomy wherein approximately half of the pancreas is resected.

Objective

The aim of this prospective study was to investigate the incidence of and risk factors for diabetes after pancreaticoduodenectomy.

Methods

This study is a part of an ongoing prospective study, the Kindai Prospective Study on Metabolism and Endocrinology after Pancreatectomy (KIP-MEP) study. Of the 457 patients enrolled to date, 96 patients without diabetes who underwent pancreaticoduodenectomy were investigated in this study. Preoperatively, 1 month post-pancreaticoduodenectomy, and every 6 months thereafter, the glucose metabolism and endocrine function were evaluated using the 75 g oral glucose tolerance test. Various other metabolic, endocrine, and exocrine indices were also examined over a period of up to 36 months.

Results

Of the 96 patients analyzed in this study, 33 were newly diagnosed with diabetes. The cumulative diabetes incidence at 36 months following pancreaticoduodenectomy was 53.8%. The preoperative insulinogenic index and ΔC-peptide in the glucagon stimulation test were significantly lower in the progressors to diabetes than in the nonprogressors. Multivariate Cox regression analysis demonstrated that the insulinogenic index was the only significant risk factor for new-onset diabetes.

Conclusion

The majority of patients developed new-onset diabetes after pancreaticoduodenectomy, and a low value of the insulinogenic index was suggested to be a risk factor for diabetes. Preoperative assessment for the prediction of the onset of diabetes serves as useful information for patients and is important for postoperative glycemic control and diabetes management in patients who require pancreaticoduodenectomy.
Negatively Charged Clay Particles Influence Spectroscopic Properties of Anionic Organic Dyes in Aqueous Colloids
Authors: Nakato Teruyuki , Kawanami Yoshiki , Taninaka Keisuke , Mouri Emiko
Published: September 2022

Aqueous colloids of smectite-type clays have been employed as heterogeneous media for photofunctional dyes, where negatively charged clay particles adsorb cationic and polar dye molecules through electrostatic immobilization. However, we herein demonstrate impacts of negatively charged hectorite clay particles on the spectroscopic behavior of anionic dyes. Anionic Eosin B dissolved in aqueous clay colloids exhibits spectroscopic behavior reflecting the coexisting clay particles. The absorption and fluorescence maxima are red-shifted and the fluorescence is intensified with increasing clay concentration. Removal of the clay particles by ultracentrifugation recovers the spectra of aqueous solution, indicating attractive interactions between the anionic dye molecules and negatively charged clay particles. Moreover, the spectroscopic impacts of the clay particles vary on both the dye species and clay mineral species; spectroscopic properties of Rose Bengal are not greatly affected by the clay particles, and synthetic saponite more influences the absorption and emission spectra of the dyes.
Dark Matter in (Volatility and) Equity Option Risk Premiums
Authors: Bakshi Gurdip , Crosby John , Gao Xiaohui
Published: September 2022

In their paper, “Dark Matter in (Volatility and) Equity Option Risk Premiums,” Bakshi, Crosby, and Gao ask a provocative question: is there dark matter embedded in volatility and equity options? They consider a theoretical approach that allows them to introduce the constructs of risk premiums on jumps crossing the strike and on local time. The treatment of jumps crossing the strike and local time is integral to their theory because their absence would be counterfactual from an empirical standpoint. They label such abstract uncertainties—driven by unspanned risk components—“dark matter” as these uncertainties can be hard to identify, but their presence is implied in options data, and the workings of dark matter can be economically influential. Their empirical exercises are based on weekly equity index options (the “weeklys”) in addition to the farther-dated (index and futures) options up to 88 days maturity.
Transforming Children's Live Experiences with Species into Conservation Willingness: The Mediating Roles of Biodiversity Knowledge and Affective Attitudes
Authors: Faruhana Abdullah , Asniza Ishak Nor , Zohir Ahmad Mohammad
Published: September 2022

The loss of direct experiences with nature among today's children is of concern as it affects their conservation willingness (CW). While little is known about the influence of live experiences on CW, much less is known about how these events are related. This study aimed to examine the serial mediating effects of biodiversity knowledge (BK) and affective attitudes (AA) on the relationship between live experiences with species and CW. An online questionnaire was administered to 429 school children (11-12 years) in the Maldives. A two-serial mediation analysis revealed that live experiences exerted significant negative direct and positive indirect effects on CW. Thus, although a predictive sequential pathway from live experiences to BK to AA to CW was confirmed, partial mediation involving other mediators or moderators is likely. The direct effects of live experiences on BK and AA and of BK on AA suggest that experiential learning that stimulates AA is necessary to achieve overall positive impacts on CW. Therefore, educators and policymakers are critical in providing first-hand experiences to instill positive biodiversity conservation traits in children, enabling successful education for sustainable development and long-term biodiversity conservation.
“This has definitely opened the doors”: Provider perceptions of patient experiences with telemedicine for contraception in Illinois
Authors: Song Bonnie , Boulware Angel , Wong Zarina Jaffer , Huang Iris , Whitaker Amy K. , Hasselbacher Lee , Stulberg Debra
Published: September 2022

Context

The COVID‐19 pandemic increased the provision of contraception through telemedicine. This qualitative study describes provider perceptions of how telemedicine provision of contraception has impacted patient care.

Methods

We interviewed 40 obstetrics‐gynecology and family medicine physicians, midwives, nurse practitioners, and support staff providing contraception via telemedicine in practices across Illinois, including Planned Parenthood of Illinois (PPIL) health centers. We analyzed interview content to identify themes around the perceived impact of telemedicine implementation on contraception access, contraceptive counseling, patient privacy, and provision of long‐acting reversible contraception (LARC).

Results

Participants perceived that telemedicine implementation improved care by increasing contraception access, increasing focus on counseling while reducing bias, and allowing easier method switching. Participants thought disparities in telemedicine usage and limitations to the technological interface presented barriers to patient care. Participants' perceptions of how telemedicine implementation impacts patient privacy and LARC provision were mixed. Some participants found telemedicine implementation enhanced privacy, while others felt unable to ensure privacy in a virtual space. Participants found telemedicine modalities useful for counseling patients considering methods of LARC, but they sometimes presented an unnecessary extra step for those sure about receiving one at a practice offering same day insertion.

Conclusion

Providers felt telemedicine provision of contraception positively impacted patient care. Improvements to counseling and easier access to method switching suggest that telemedicine implementation may help reduce contraceptive coercion. Our findings highlight the need to integrate LARC care with telemedicine workflows, improve patient privacy protections, and promote equitable access to all telemedicine modalities.
Lymphography method based on time-autocorrelated optical coherence tomography
Authors: Lian Yi , Li Tingfeng , Wu Nanshou , Wu Jiayi , Tang Zhilie
Published: September 2022

Lymphatic vessels are structurally similar to blood vessels, and the lymphatic fluid flowing within the lymphatic vessels is distributed throughout the body and plays a vital role in the human immune system. Visualization of the lymphatic vessels is clinically important in the diagnosis of tumor cell metastasis and related immune system diseases, but lymph is difficult to image due to its near-transparent nature and low flow rate. In this paper, we present a lymphography method based on time-autocorrelated optical coherence tomography. By using the minimum value difference of the autocorrelation function of the time-varying interference intensity between the lymph and the surrounding tissues, the non-invasive and high-sensitivity imaging of lymph vessels can be achieved. The method proposed in this paper has potential significance for the research and treatment of immune system diseases.
Application of XUV Free-Electron Radiation for Opacities of Highly Ionized Atoms
Authors: Merts A. L.
Published: September 2022

The primary requirement for transport of radiation through a material media is to have estimates for the absorption coefficients at the appropriate wavelengths. For many applications, the appropriate wavelengths are determined by the temperature of the material in question. In many other cases where the source of radiation is not characterized by the local temperature, one needs a versatile source of radiation continuously covering a wavelength interval appropriate for the problem at hand.
Low-order nonlinearities and high-order harmonics generation in Zn and ZnSe nanoparticles synthesized during femtosecond laser ablation at a 50  kHz pulse repetition rate
Authors: Boltaev Ganjaboy S. , Abu Baker Aya M. , Iqbal Mazhar , Abbasi Naveed A. , Reyimboev Sherzod B. , Ganeev Rashid A. , Alnaser Ali S.
Published: September 2022

We synthesize Zn and ZnSe nanoparticles during laser ablation of bulk material in ethanol and analyze them using the Z-scan technique and the generation of high harmonics using a 50 kHz, 40 fs, and 1030 nm laser. The low-order nonlinear absorption and nonlinear refraction coefficients in the colloidal suspensions of the formed nanoparticles were measured using 1030 nm and 515 nm probing laser pulses, respectively. The values of the nonlinear refractive index and nonlinear absorption coefficient of Zn NPs at 1030 nm wavelength were calculated to be

γ
=
−

1.4

×

10

−
13

c
m

2

W

−
1

and

β
=

2.7

×

10

−
11

c
m

W

−
1

, respectively. Similarly, in the case of ZnSe NPs,

γ
=
−

4.9

×

10

−
14

c
m

2

W

−
1

and

β
=

0.5

×

10

−
11

c
m

W

−
1

, respectively. In the case of 515 nm probing pulses, the corresponding nonlinear optical parameters of Zn NP suspension were calculated to be

γ
=
−

1.7

×

10

−
14

c
m

2

W

−
1

and

β
=

1.0

×

10

−
11

c
m

W

−
1

, and for ZnSe NP suspension, the value of β was calculated to be

2.1

×

10

−
11

c
m

W

−
1

. The nonlinear refractive index of this suspension was

γ
=
−

2.4

×

10

−
14

c
m

2

W

−
1

. We also report the studies of high-order harmonics generation in plasmas containing Zn and ZnSe NPs using single- (1030 nm) and two-color (1030 nm + 515 nm) laser fields. The maximal generated extreme ultraviolet (XUV) harmonics were 33rd (Zn NPs) and 27th (ZnSe NPs) orders. The decrease of the maximal generating harmonic orders was explained using the three-step model. The high brightness of the ninth and 10th harmonics generated in the two-color laser field was obtained due to the resonance properties of Zn NPs. The maximal generated XUV harmonics were the 33rd (Zn nanoparticles) and 27th (ZnSe nanoparticles) orders.
Ultralow Threshold Oxide/Semiconductor DBR VCSELs for Application to Smart Pixels
Authors: Dapkus P. Daniel , MacDougal Michael H. , Lin Chao-Kun , Bond Aaron , Geske Jonathon
Published: September 2022

Ultralow threshold vertical cavity lasers promise to revolutionize free space optical systems. This talk will discuss VCSEL structures that can be utilized in a flexible smart pixel technology.
Detection and classification of structural defects on textured surfaces
Authors: Schwarzer Heiko , Teiwes Stephan
Published: September 2022

Automated product inspection is a highly important issue in industrial manufacturing. A typical problem is the examination of structured surfaces of fabricated items in order to identify defects. Usually, one has to deal with ”endless” materials transported at high speeds, such as breadths of cloth, carpet, plastic foil, or the like. These materials possess a surface texture that is characterized by a certain global regularity but also by slight local variations of indeterministic nature. Fabrication errors can be identified as structures that violate the global regularity. An example for a common cloth texture carrying a typical fabrication error is depicted in the leftmost image of fig. 2. The examination procedure can be divided into the detection and the classification of defects. Whereas the primary goal of the detection is to localize all irregularities, the latter part refers to the distinction of different defect types.
GaAs Smart Pixel Arrays for High Performance Optoelectronic Computing Modules
Authors: McCallum D. S. , Kim J. W. , Guilfoyle P. S. , Chang W. H. , Mu J. , Feng M.
Published: September 2022

Optoelectronic logic gates interconnected by free space optics (smart pixels) show great promise for efficient implementation of high performance switching, signal processing, and computing systems. Optical interconnects have a number of advantages over electrical interconnects, including (1) lower energy per bit for point to point interconnections; (2) lower chip area used per interconnection which allows a larger interconnect density; and (3) ability to implement high fan-out and high fan-in processing architectures. OptiComp is currently developing smart pixel arrays in GaAs and Si which will contain up to 1,000 smart pixels, each operating at a data rate of hundreds of Mb/s, on a 1 cm2 die. In this paper, we will describe the design of GaAs-based smart pixel arrays which contain up to 8 x 8 elements in a 9 x 9 mm area, and which are projected to operate at data rates in excess of 1 Gb/s/channel. These smart pixel arrays are suitable for incorporation in high performance optoelectronic computing (HPOC) modules.
A Generalized Family of Optical Receivers for Optical Interconnects
Authors: Shang A. Z. , Tooley F. A. P.
Published: September 2022

Optical energy is limited in any optical interconnect system. Therefore we require an amplifier to decrease the optical energy for data communication. Electrical power consumed by this amplifier reduces the optical power required. An optical receiver for parallel interconnected systems (e.g., optical interconnected VLSI chips) must be moderately sensitive (-30 dBm to -20 dBm), low- electrical power (< 7 dBm), and high-speed (bit rate, B, in the hundreds of Mb/s). It also needs to be low-noise. A small dynamic range (<3 dB) can usually be tolerated since the optical power level can be set to this accuracy. The challenge in VLSI optical receiver design is to meet the above requirements simultaneously [1].
VCSEL-based Free-Space Optical Interconnect with Integrated Microlenses
Authors: Strzelecka E.M. , Bertilsson K. , Louderback D. , Thibeault B.J. , Thompson G.B. , Coldren L.A.
Published: September 2022

Increasing computer clock speed is the motivation for investigating the use of optics in comupter interconnects. The technology that will eventually replace electrical interconnects must feature high speed and low power consumption at a low cost to the end user. Vertical cavity surface emitting laser (VCSELs) arrays have become viable candidates for transmiters in optical links [1-2]. Their low threshold currents (< 300 µA for ~ 4 µm diameter devices), relatively low power consumption, and low operating voltage (< 2 V) [3-4], make them compatible with simple drive circuits. High modulation bandwidth can be achieved without additional pre-bias circuitry. VCSELs with a record 3 dB bandwidth of 15.3 GHz at only 2.1 mA of bias current have been reported [5]. Furthermore, highly divergent beams from small diameter devices are compatible with microoptics integrated on the same substrate. The beams reaching the back side of the substrate fill integrated microlenses enabling high numerical aperture (NA) focusing or collimation into low diffraction beams. With these integrated components, coupling into fibers and collimation for free-space systems can be realized with no external optics. We demonstrate a free-space optical link consisting of arrays of substrate emitting VCSELs as transmitters and back-side illuminated double-pass Schottky photodiodes as receivers. These devices are integrated on-chip with microlenses etched on the back side of the substrate [6]. Analysis and test results of the system’s tolerance to mechanical misalignments are presented.
Spatial-Spectral Holographic Memories, Processor, and Routers
Authors: Babbitt Wm. Randall
Published: September 2022

Traditional spatial holographic devices are based on modification of the absorptive or dispersive properties of recording materials with dimensionality of one (gratings), two (holographic plates), or three (volume holograms). In this paper, the interest is in materials that, in addition to possessing the familiar spatial selectivity, respond selectively to various spectral components of the incident light. Spatial-Spectral Holographic (SSH) materials can implement all the processes associated with traditional spatial holography while simultaneously recording and processing the spectral/temporal characteristics of optical fields. Several memory, processing, routing, and communication devices have been proposed and demonstrated based on SSH.[1-15]
Man-machine interfaces using image information obtained by a 32x32-pixel artificial retina chip
Authors: Toyoda Takashi , Miyake Yasunari , Tanno Hiroshi , Nitta Yoshikazu , Funatsu Eiichi , Freeman W. T. , Ohta Jun , Kyuma Kazuo
Published: September 2022

The image is one of the most suitable information input representations for future multimedia systems. However, it is difficult for conventional charge coupled device (CCD) systems to handle such image information, especially in high speed image processing such as motion picture processing. This is caused by the limitation of the frame rate of the CCD (1/60-1/30sec) and by the bus capacity between the CCD and the computer. To solve the problem of this transmission bottle neck, we have proposed a novel type of image sensor, an artificial retina (AR) chip, and we have demonstrated flexible and high-speed on-chip processing capabilities of the chip [1].
Two-Photon Based Three-Dimensional Optical Memories: Resolution and Crosstalk Issues
Authors: Urey Hakan , McCormick Frederick B.
Published: September 2022

There are several approaches for 3-D optical storage. 2-photon absorption technique allocates a unique physical location for each bit.1,2 Motivation for this research is to determine and maximize storage capacity and data transfer rate using inexpensive off-the-shelf optical components. This can be achieved by adjusting the system apertures and bit-duty-cycles.
Compact Free-Space Multistage Interconnection Network Demonstration
Authors: Marom Dan M. , Shames Paul , Xu Fang , Rao Ramesh R. , Fainman Yeshayahu
Published: September 2022

Communication between large numbers of I/O ports will require switching of Terabit aggregate bandwidth to meet the needs of future applications. Advances in fiber amplifiers have increased interest in transparent optical networks which do not rely on data regeneration in the electronic domain. Additionally, since polarization compensation in a single mode fiber [1] allows automatic and stable control of the polarization states of transmitted optical signals, it may enable utilization of polarization dependent all-optical switches. Polarization switching has been proposed for ‘free-space’ multistage interconnection networks (MIN) for switching and multiprocessor interconnections [2-5]. In this paper we present a ‘folded’ optical MIN system that permits switching high-speed signals between multiple input and output nodes. Optical routing is performed by bypass-exchange switches built of birefringent computer generated holograms (BCGH) combined with electrically addressed ferroelectric liquid crystal (FLC) device. This scaleable system can switch high bandwidth communication lines or permit memory access and multiprocessor interconnections. In the following we discuss the system design, network protocol, and performance of our optical MIN.
Distributed Path Management in Switched Optical Banyan Networks1
Authors: Salisbury C. , Melhem R. , Qiao C.
Published: September 2022

Optical networks for interconnecting massively parallel processor systems have the potential to provide high bandwidth, low latency communication paths. Circuit switching networks exploit this bandwidth by providing all-optical connections between a set of sources and destinations. This increases the complexity of managing the network, since the connections must be changed in a systematic way to provide the complete set of paths required by the application.
Error-free Transmission in Optical Space-CDMA for 2-D Parallel Data Links
Authors: Nakamura Moriya , Kitayama Ken-ichi
Published: September 2022

Code division multiple access (CDMA) is an asynchronous, random access protocol. In conventional time-domain CDMAs, each data bit is encoded into a waveform which corresponds to a signature code sequence [1], [2]. We have proposed and experimentally demonstrated a space-CDMA for parallel transmission aiming at the applications to future high-throughput 2-D parallel data links connecting massively parallel processors of a number of data bits regularly aligned on two-dimensional (2-D) grids, so-called bit-planes [3], [4].
The Cost of Optical Interconnects vs MCMs
Authors: Stirk Charles W. , Neff John
Published: September 2022

The goal of this paper is to investigate the impact that cost and yield have on the organization of optically interconnected computer architectures. To measure cost, we build analytic abstractions of the economics of the manufacturing process parameterized in terms of the individual fabrication step costs and yield, and the physical and logical architecture characteristics. These composite architecture-cost models are used to calculate the cost-optimum number of chips in a solder-bumped VCSEL array. For large shuffle-exchange networks with wide channels, the models predict that optical interconnects with VCSEL-solder-CMOS can be lower cost than the all electrically interconnected CMOS/MCM.
Optimization and Operation of Surface Normal, Low Voltage Electro-absorption Modulators
Authors: Tooley Frank A. P. , Neilson David T. , Ryvkin Boris , Currie John , Richard Edwis , Wasilewski Zbig , SpringThorpe Tony
Published: September 2022

In order to be compatible with the silicon industry it is desirable to put optical transceivers directly on processed silicon chips, so that the optical signals terminate directly on-chip. These transceivers require a detector and transmitter which could be either an emitter or a modulator. One promising route for the construction of such hybrid chips is to flip-chip bond III-V devices as detectors and modulators[1-4] to CMOS. This poster will present measurements of the performance of electro-absorption modulators we have designed, grown and fabricated which are intended to be flip-chipped bonded to CMOS. In addition, we will also describe our work on the optimization of these structures[5] and compare the low voltage performance of bulk GaAs modulators with MQW GaAlAs/GaAs modulators [7].
Time-differential operation of an optical receiver
Authors: Tooley Frank , Sinha Pritam , Shang Alain
Published: September 2022

The optical receiver is one of the most critical components in any optical system design. This paper will compare receiver operating modes and introduces a novel approach which enhances system robustness to optical power non-uniformity. The receiver dynamic range is of critical concern. The source of this variation in signal level can be due to the characteristics of the transmitter, the optical interconnect and the receiver.
Chip-on-board packaging of a Hybrid-SEED smart pixel array
Authors: Kabal D. , Ayliffe M. H. , Boisset G. C. , Plant D. V. , Rolston D. R. , Venditti M. B.
Published: September 2022

Providing an integrated packaging solution for a two-dimensional smart pixel array presents a series of constraints that complicate the employment of standard electronic packaging in systems applications. Through the construction of demonstrator systems, the Photonic Systems Group at McGill University (PSG McGill) has designed, fabricated, and implemented smart pixel array packaging which uniquely addresses the critical issues associated with successfully integrating two-dimensional optoelectronic device arrays into systems. These system design considerations are: electrical bandwidth, electrical connectivity, thermal management, and optomechanical interfacing.
Recurrent Optical Neural Network for the Study of Pattern Dynamics
Authors: Berger Christoph , Collings Neil , Jost Timothée
Published: September 2022

The goal of our current research is to investigate the dynamics of patterns circulating in an asynchronous recurrent neural network. We have designed a recurrent neural network with 16×16 fully interconnected channels and an optical feedback loop. Initial experimental results with building blocks of the system are presented.
Evaluations of Optical Parallel Digital Discrete Correlators
Authors: Awatsuji Yasuhiro , Tanida Jun , Ichioka Yoshiki
Published: September 2022

Optical computing is a powerful information processing paradigm for massively data owing to attractive features of light such as parallelism, flexible connectivity, high density connectivity. Digital optical computing is most promising because of accuracy and processing flexibility. Several paradigm of digital optical computing have been proposed. [1-4]. These paradigms can provide space-invariant logical operations for digital and discrete image in parallel. In processing sequences of the paradigms, digital discrete correlation is considered as an essential operation. Efficiency of optical parallel digital discrete correlator (OPDDC) determines that of optical digital computing system. Although a lot of implementation have been presented, there are few systematic study on this subject.
Hybrid Technology for Optoelectronic Parallel Processing : Basic Considerations and Future Trends
Authors: Desmulliez M.P.Y. , Foulk P.W. , Wherrett B.S.
Published: September 2022

The combined exploitation of free-space optical interconnections and very large scale integrated (VLSI) electronics has recently allowed the construction of demonstrator systems [1,2] which exhibit on/off chip communication rates at least one order of magnitude greater than that of electronic systems. A recent article shows that the maximum on/off chip communication rate of the CMOS-SEED bitonic sorter built by the Scottish Collaboration Initiative in Optoelectronic Sciences (SCIOS) is 5.2 1011 pin-Hz [3]. This technology, called hybrid or smart-pixel-array technology, has provoked studies of the issues involved in determining the complexity of each processing element (the pixel) in order to optimize the overall system performance [3-5]. In order to contribute to the debate, the purpose of this article is fourfold: (i) to show that such performance relies on a small set of parameters which characterize the processing element in the optical and electronic domains as shown in table 1, (ii) to demonstrate that optimum performance lies in a narrow niche of the resulting parameter space, (iii) to indicate which technology has to be improved in order to harvest the full communication rate of such systems, and (iv) to outline an unexpected application for which the hybrid technology could contribute significantly.
2D and 3D Equalizers for Page-Oriented Optical Memories
Authors: Wang Mark M. , McCormick Frederick B. , Esener Sadik C.
Published: September 2022

In this study we investigate the use of 2D and 3D equalizers to suppress intersymbol interference (ISI) in 2D parallel channels. The techniques demonstrated here are best suited for parallel implementation and can be used for any page-oriented readout application including increasing the data density achievable in volume optical memories or increasing the number of links achievable in free-space optical interconnects. Page-oriented optical memories are currently being investigated for their potential as high data-rate, high capacity storage devices,1-3 however the cost-effectiveness of such devices is limited by their requirements for high resolution in the optical system and severe alignment tolerances on the 2D detector array. Various techniques have been used in an attempt to reduce the amount of ISI generated by optical aberrations and misalignment including the use of guard bands around each bit and also reduced fill-factor detectors,2,3 however such techniques have the undesirable result of also reducing the signal intensity of each bit. An alternative approach is to remove the crosstalk electronically after detection. Serial equalizers have been used for years in communications and storage channels as a method of reducing ISI in a temporal bit stream.4 Limited 2D equalizers have also been demonstrated to reduce inter-track interference in high density optical disc recordings with multiple-beam readout heads.5-7 The use of partial-response maximum-likelihood (PRML) detection has been demonstrated to reduce the effects of crosstalk in page-oriented memories, however the complexity of PRML detectors increases rapidly as the number of spatial dimensions and the number of possible states increases.8 In this paper we propose the design of 2D and 3D equalizers suitable for page-access optical memories and investigate the performance of both linear and decision feedback implementations.
AIoT enabled resampling filter for temperature extraction of the Brillouin gain spectrum
Authors: Wang Ming Hai , Sui Yang , Zhou Wei Nan , An Xin , Dong Wei
Published: September 2022

The Artificial Intelligence of Things (AIoT) turns passive fiber sensors into learning machines. It can be used to integrate intelligent nodes into a multi-dimensional sensing system. In this study, the temperature measurement system based on Brillouin Gain Spectrum (BGS) test setup is creatively implemented with the AIoT architecture; the training and testing stages of the neural network are divided into different layers of equipment to improve performance and reduce the network traffic. To enable the lightweight and low-power consumption edge computing device to extract accurate temperature from the BGS during testing, we have integrated the post-processing method inspired by curve fitting into the machine learning and proposed the efficient digital resampling filter. The resampling filter approach is achieved by the peak range algorithm with Gauss differential operator and digital band-pass filter. The evaluation results for different methods on the BGS datasets show the superior performance of our approach. Notably, the approach can increase temperature extraction accuracy and compress the sampling data. The RMSEA of the extraction temperature is 0.5635, which can bring an almost 21% accuracy increase over the classic method. Compared with the classic method of processing the original data on the same hardware platform, the amount of data post-processed by the filter is reduced by 75%; the time consumption is reduced by 22%.
High-accuracy camera calibration method based on coded concentric ring center extraction
Authors: Yu Jin , Liu Yue , Zhang Zonghua , Gao Feng , Gao Nan , Meng Zhaozong , Jiang Xiangqian
Published: September 2022

In the field of three-dimensional (3-D) metrology based on fringe projection profilometry (FPP), accurate camera calibration is an essential task and a primary requirement. In order to improve the accuracy of camera calibration, the calibration board or calibration target needs to be manufactured with high accuracy, and the marker points in calibration image require to be positioned with high accuracy. This paper presents an improved camera calibration method by simultaneously optimizing the camera parameters and target geometry. Specifically, a set of regularly distributed target markers with rich coded concentric ring pattern is first displayed on a liquid crystal display (LCD) screen. Then, the sub-pixel edges of all coded bands radial straight lines are automatically located at several positions of the LCD screen. Finally, the sub-pixel edge point set is mapped into parameter space to form a line set, and the intersection of the lines is defined as the center pixel coordinates of each target point to complete the camera calibration. The simulation and experimental results verify that the proposed camera calibration method is feasible and easy to operate, which can essentially eliminate the perspective transformation error to improve the accuracy of camera parameters and target geometry.
Multi-spectral radiation thermometry based on an Alpha spectrum-LM algorithm under the background of high temperature and intense reflection
Authors: Chen Liwei , Zhang Xianqi , Gao Shan , Cui Ying , Yang Can , Wei Xiaokai , Jiang Jing , Niu Yi , Wang Chao
Published: September 2022

In order to meet the needs of multi-spectral radiation temperature measurement under high temperature background, this paper studies the problems of reflected radiation interference and spectral emissivity difficult to obtain in high temperature and intense reflection environment. First, using discrete triangular surface elements and radiation angle coefficients, an analysis model of high temperature background reflected radiation is constructed to describe the variation characteristics of high temperature background reflected radiation. Secondly, the least squares support vector machine (LSSVM) is optimized by particle swarm optimization (PSO) algorithm, and an emissivity model identification algorithm based on Alpha spectrum-Levenberg Marquarelt (LM) algorithm is proposed, which has stronger applicability and accuracy than existing emissivity model identification methods. Finally, the high temperature background radiation and the emissivity model are combined to construct and solve the multi-spectral target equation, so as to realize the reflected radiation error correction and radiation temperature measurement under the high temperature and intense reflection background. The simulation and experimental comparison with the existing methods show that the temperature measurement error of the radiation temperature measurement method proposed in this paper is below 9.5K, which can effectively correct the reflected radiation error and further improve the temperature measurement accuracy.
Generation of a higher-order Poincaré sphere beam array with spatial coherence engineering
Authors: Liu Yonglei , Dong Zhen , Wang Fei , Chen Yahong , Cai Yangjian
Published: September 2022

We propose a protocol to synthesize a class of vector beam array in the far field with periodic higher-order Poincaré sphere (HOPS) polarization states by engineering the second-order spatial coherence structure of a partially coherent light source. We show that the polarization state of a single HOPS beam at the source plane can be mapped into a beam array in the far field when the spatial coherence of the beam source is engineered to have a lattice-like distribution. We demonstrate that the degree of polarization of the generated HOPS beam array can be conveniently controlled by modulating the transverse spatial coherence width of the source. Our method provides an additional way to construct the structured beam array and may find applications, e.g., in multiparticle manipulations.
Quasi-monolithic heterodyne laser interferometer for inertial sensing
Authors: Zhang Yanqi , Guzman Felipe
Published: September 2022

We present a compact heterodyne laser interferometer developed for high-sensitivity displacement sensing applications. This interferometer consists of customized prisms and wave plates assembled as a quasi-monolithic unit to realize a miniaturized system. The interferometer design adopts a common-mode rejection scheme to provide a high rejection ratio to common environmental noise. Experimental tests in vacuum show a displacement sensitivity level of

11

p
m

/

H
z

at

100

m
H
z

and as low as

0.6

p
m

/

H
z

above

1

p
m

. The prototype unit is

20

m
m

×

20

m
m

×

10

m
m

in size and weighs

4.5

g

, allowing subsequent integration in compact systems.
Demonstration of a CMOS Static RAM Chip with High-Speed Optical Read and Write
Authors: Krishnamoorthy A. V. , Rozier R. G. , Ford J. E. , Kiamilev F. E.
Published: September 2022

In the last three decades, random access memory (RAM) densities have progressed at an incredible rate, from the early 1 Kilobit chips to the 1 Gigabit DRAMs that have recently been produced [1]. Similar progress has been made in the development of micro-processors, with 64-bit RISC processors now operating at 450MHz, and GHz processors on the horizon [2]. Data transfer rates from high-density memories to processors have not, however, followed this growth curve, producing an increasing gap between memory and processor bandwidths. This has created an opportunity for new techniques for high-speed data transfer from main memory.