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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 319: 124582, 2024 Oct 15.
Article En | MEDLINE | ID: mdl-38833883

Fluorescence spectroscopy coupled with a random forest machine learning algorithm offers a promising non-invasive approach for diagnosing glycosuria, a condition characterized by excess sugar in the urine of diabetic patients. This study investigated the ability of this method to differentiate between diabetic and healthy control urine samples. Fluorescent spectra were captured from urine samples using a Xenon arc lamp emitting light within the 200 to 950 nm wavelength range, with consistent fluorescence emission observed at 450 nm under an excitation wavelength of 370 nm. Healthy control samples were also analyzed within the same spectral range for comparison. To distinguish spectral differences between healthy and infected samples, the random forest (RF) and K-Nearest Neighbors (KNN) machine learning algorithms have been employed. These algorithms automatically recognize spectral patterns associated with diabetes, enabling the prediction of unknown classifications based on established samples. Principal component analysis (PCA) was utilized for dimensionality reduction before feeding the data to RF and KNN for classification. The model's classification performance was evaluated using 10-fold cross-validation, resulting in the proposed RF-based model achieving accuracy of 96 %, specificity of 100 %, sensitivity of 93 %, and precision of 100 %. These results suggest that the proposed method holds promise for a more convenient and potentially more accurate method for diagnosing glycosuria in diabetic patients.


Algorithms , Glycosuria , Machine Learning , Principal Component Analysis , Spectrometry, Fluorescence , Humans , Spectrometry, Fluorescence/methods , Glycosuria/diagnosis , Glycosuria/urine , Diabetes Mellitus/urine , Diabetes Mellitus/diagnosis , Male , Female
2.
Opt Express ; 32(11): 19438-19448, 2024 May 20.
Article En | MEDLINE | ID: mdl-38859078

In this paper, a secure orthogonal time-frequency space (OTFS) modulation transmission system based on 3D dense constellation mapping (DCM) geometric shaping is proposed, and a selective reduction amplitude algorithm (SRA) for DCM to reduce peak average power ratio (PAPR) is presented. The DCM is based on regular tetrahedron construction to improve its space utilization efficiency. The proposed SRA involves reducing high PAPRs transmitter and restoring them at the receiving end, which only requires an additional 0.57% of the total transmission capacity. The algorithm reduces PAPR while ensuring the bit error rate performance of the system, so it is suitable for systems that need to process large amounts of transmitted data quickly. By verifying the actual transmission performance on a 2 km of 7-core optical fiber transmission system, the optical transmission with a bit rate of 33.93Gb/s is achieved. The experimental results show that when the bit error rate (BER) reaches the 3.8×10-3 threshold, the OTFS system using DCM and SRA could improve the receiver sensitivity by 3.7 dB compared with the OTFS system using concentric cube mapping and SRA, and 2.7 dB compared with the OFDM system using DCM. After adding the SRA, the PAPR of the OTFS system is reduced by more than 2.2 dB. When the received optical power reaches near the bit error rate threshold, the SRA valid data can be fully recovered by optimizing the SRA.

3.
Opt Express ; 32(11): 19984-19998, 2024 May 20.
Article En | MEDLINE | ID: mdl-38859118

This paper proposes a high-security multidimensional data protection system based on the Hartley algorithm-driven chaotic scheme. We utilize the fast Hartley algorithm instead of the fast fourier computation, and we employ chaotic sequences generated by the multi-winged chaotic system to achieve chaos-driven 3D constellation mapping, effectively integrating the chaotic system with the stochastic amplitude modulator. We reduce the signal's peak-to-average power ratio (PAPR) by deploying a random amplitude modulator. Simultaneously, this approach enhances the security of the physical layer of the signal. The PAPR reduction can reach up to 2.6 dB, while the most robust and stable modulator scheme can gain 2 dB. Finally, in the Hartley frequency domain, the signal's frequency is disrupted, providing the entire system with a key space of 10131 to resist violent cracking and thus improving the system's overall security. To validate the feasibility of our scheme in comparison to conventional IFFT-based encrypted 3D orthogonal frequency division multiplexing, We achieved a transmission rate of 27.94 Gb/s over a 2 km multicore fiber. Experimental results show that since the random amplitude generator effectively reduces PAPR, our proposed encryption scheme increases the forward error correction threshold range by 1.1 dB, verifying that our proposed scheme has highly reliable security performance.

4.
Opt Express ; 32(12): 20515-20527, 2024 Jun 03.
Article En | MEDLINE | ID: mdl-38859432

In this paper, we propose a method for training a key-enhanced chaotic sequence using the convolutional long short term memory neural network (CLSTM-NN) for secure transmission. This method can cope with the potential security risk posed by the degradation of chaotic dynamics when using chaotic model encryption in traditional secure transmissions. The simulation results show that the proposed method improves the key space by 1036 compared to traditional chaotic models, reaching 10241. The method was applied to orthogonal chirp division multiplexing (OCDM). To demonstrate the feasibility of the proposed scheme, we conducted transmission experiments of encrypted 16 quadrature amplitude modulation (QAM) OCDM signals at a speed of 53.25 Gb/s over a 2 km length of 7-core optical fiber and test different encryption schemes. After key enhancements, the overall number of keys in the system can increase from 18 to 105.The results show that there is no significant difference between the bit error rate (BER) performance of the encryption method proposed in this paper and the traditional encryption method. The maximum performance difference between the different systems does not exceed 1 dBm. This fact proves the feasibility of the proposed scheme and provides new ideas for the next generation of secure transmission.

5.
Opt Express ; 32(12): 21258-21268, 2024 Jun 03.
Article En | MEDLINE | ID: mdl-38859484

In this paper, we propose a high-security space division multiplexing optical transmission scheme based on constellation grid selective twisting, which adopts the Rossler chaos model for encrypting PDM-16QAM signals, being applied to a multicore, few-mode multiplexing system. The bitstream of the program is passed through XOR function before performing constellation grid selective twisting and rotation of the constellation map to improve the security of the system. The proposed system is verified experimentally by using 80-wave and 4-mode multiplexing in one of the 19-core 4-mode fibers. Based on the proposed encryption method, a net transmission rate of 34.13 Tbit/s, a transmission distance of 6000 km, and a capacity distance product of 204.8 Pb/s × km is achieved under encrypted PDM-QPSK modulation. Likewise, a net transmission rate of 68.27 Tbit/s, a transmission distance of 1000 km, and a capacity distance product of 68.27 Pb/s × km is achieved based on encrypted PDM-16QAM modulation. It is experimentally verified that the sensitivity of the initial value in Rossler's chaotic model is in the range of 10-16∼10-17. Meanwhile, the proposed encryption scheme achieves a large key space of 10101, which is compatible with the high-capacity distance product multicore and few-mode multiplexing system. It is a promising candidate for the next-generation highly-secured high-capacity transmission system.

6.
Opt Express ; 32(6): 9671-9685, 2024 Mar 11.
Article En | MEDLINE | ID: mdl-38571196

In this paper, we propose a high spectral efficiency modulation scheme based on joint interaction of orthogonal compressed chirp division multiplexing (OCCDM) and power superimposed code (PSC) under the intensity modulation and direct detection (IM/DD) system. OCCDM is a novel orthogonal chirp division multiplexing technology featuring spectral compression through the implementation of processing similar to a discrete Fourier transform, enhancing the spectral efficiency (SE) through bandwidth savings without loss of orthogonality of each chirp. Meanwhile, PSC technology enables multiple code words being transmitted superimposed on the same chirp. This technique involves allocating varying power levels to different users, thereby distinguishing them, increasing the transmission's net bit rate and substantially boosting the SE. The transmission has been performed experimentally using a 2 km 7-core fiber span. The impact of the above-mentioned technologies on the bit error rate (BER) performance is assessed in the power, frequency, and joint domain. The BER and enhancements in the SE can be balanced when the spectral bandwidth compression factor (α) and power distribution ratio are equal to 0.9 and 4, respectively. The observed outcome leads to the transmission's SE increase to more than double the baseline value, at 2.22 times. Based on the above analysis, we believe this structure is expected to become a potential for developing next-generation PON.

7.
PeerJ Comput Sci ; 10: e1833, 2024.
Article En | MEDLINE | ID: mdl-38660213

With the emergence of Internet of Things (IoT) technology, a huge amount of data is generated, which is costly to transfer to the cloud data centers in terms of security, bandwidth, and latency. Fog computing is an efficient paradigm for locally processing and manipulating IoT-generated data. It is difficult to configure the fog nodes to provide all of the services required by the end devices because of the static configuration, poor processing, and storage capacities. To enhance fog nodes' capabilities, it is essential to reconfigure them to accommodate a broader range and variety of hosted services. In this study, we focus on the placement of fog services and their dynamic reconfiguration in response to the end-device requests. Due to its growing successes and popularity in the IoT era, the Decision Tree (DT) machine learning model is implemented to predict the occurrence of requests and events in advance. The DT model enables the fog nodes to predict requests for a specific service in advance and reconfigure the fog node accordingly. The performance of the proposed model is evaluated in terms of high throughput, minimized energy consumption, and dynamic fog node smart switching. The simulation results demonstrate a notable increase in the fog node hit ratios, scaling up to 99% for the majority of services concurrently with a substantial reduction in miss ratios. Furthermore, the energy consumption is greatly reduced by over 50% as compared to a static node.

8.
Sensors (Basel) ; 24(4)2024 Feb 07.
Article En | MEDLINE | ID: mdl-38400231

This study proposes and presents a new central office (CO) for the optical metro access network (OMAN) with an affordable and distinctive switching system. The CO's foundation is built upon a novel optical multicarrier (OMC) generation technique. This technique provides numerous frequency carriers that are characterized by a high tone-to-noise ratio (TNR) of 40 dB and minimal amplitude excursions. The purpose is to accommodate multiple users at the optical network unit side in the optical metropolitan area network (OMAN). The OMC generation is achieved through a cascaded configuration involving a single phase and two Mach Zehnder modulators without incorporating optical or electrical amplifiers or filters. The proposed OMC is installed in the CO of the OMAN to support the 1.2 Tbps downlink and 600 Gbps uplink transmission, with practical bit error rate (BER) ranges from 10-3 to 10-13 for the downlink and 10-6 to 10-14 for the uplink transmission. Furthermore, in the OMAN's context, optical fiber failure is a main issue. Therefore, we have proposed a possible solution for ensuring uninterrupted communication without any disturbance in various scenarios of main optical fiber failures. This demonstrates how this novel CO can rapidly recover transmission failures through robust switching a and centralized OLT. The proposed system is intended to provide users with a reliable and affordable service while maintaining high-quality transmission rates.

9.
Opt Express ; 32(2): 1979-1997, 2024 Jan 15.
Article En | MEDLINE | ID: mdl-38297738

This paper proposes a high-security chaotic encrypted power sparse coding division (CE-PSCD) scheme for 7-core fiber based on non-orthogonal multiple access (NOMA) technology. The method utilizes power multiplexing to realize parallel transmission of two signals. Joint encryption of the four-dimensional region is realized using constellation mapping encryption, carrier frequency encryption, symbol scrambling, and sparse code scrambling. What we believe to be a new dimension for encryption of autonomously designed sparse codes is proposed. Meanwhile, we hide the chaotic key in training sequence (TS) to realize the co-transmission of the key and the message. A 70 Gb/s CE-PSCD signal transmission over 2 km of 7-core fiber is demonstrated experimentally. At the limit of forward error correction (FEC) ∼3.8 × 10-3, the difference in the encrypted sensitivity among different users at the equal power level is 0.36 dB, which means that the fairness of users will not be destroyed. The key space can reach 10134, with a bit error rate (BER) of about 0.5 for brute-force cracking at illegal receivers. As long as the key bits in the hidden TS are wrong by one bit, the BER stays around 0.5. The results show no significant attenuation of the signal before and after encryption at either high or low power, verifying the high-security performance of our proposed scheme.

10.
Opt Express ; 31(22): 36123-36135, 2023 Oct 23.
Article En | MEDLINE | ID: mdl-38017768

A new optical transmitting scheme based on chaotic constant component distribution matcher (CCDM) and Polar coding was proposed. The data is first encrypted by Polar coding using a five-dimensional chaotic sequence. Then the encrypted data is divided into two paths to perform chaotic CCDM encryption operations with different schemes. Finally, the two channels are merged, and the subcarriers are scrambled. The transmission experiment of 16QAM-OFDM signal on 2 km seven-core fiber is conducted to verify the scheme's feasibility. The experimental results show that the received optical power of all ONUs is less than -15dBm when the BER of all ONUs is reduced to less than 10-3. In addition, the key space of the proposed system reaches 1085, and the security performance is further enhanced. The advantages of BER and safety performance make this two-path chaotic encrypted OFDM-PON with an optimistic application prospect in the current optical transmission systems.

11.
PLoS One ; 18(11): e0286823, 2023.
Article En | MEDLINE | ID: mdl-37967095

What are the effects of parenting styles on academic performance and how unequal are these effects on secondary school students from different gender and socioeconomic status families constitute the theme of this paper. A cross-sectional and purposive sampling technique was adopted to gather information from a sample of 448 students on a Likert scale. Chi-square, Kendall's Tau-c tests and hierarchical multiple regression analyses were used to determine the extent of the relationship among the variables. Chi-square and Kendall's Tau-c (Tc) test results established that the socioeconomic status of the respondent's family explained variation in children's academic performance due to parenting style; however, no significant difference was observed in the academic performance of students based on gender. Furthermore, hierarchal multiple regression analysis established that the family's socioeconomic status, authoritative parenting, permissive parenting, the interaction of socioeconomic status and authoritative parenting, and the interaction of socioeconomic status and permissive parenting were significant predictors (P<0.05) of students' academic performance. These predictor variables explained 59.3 percent variation in the academic performance of children (R2 = 0.593). Results of hierarchal multiple regression analysis in this study ranked ordered the most significant predictors of the academic performance of children in the following order. Family socioeconomic status alone was the strongest predictor (ß = 18.25), interaction of socioeconomic status and authoritative parenting was the second important predictor (ß = 14.18), authoritative parenting alone was third in importance (ß = 13.38), the interaction of socioeconomic status and permissive parenting stood at fourth place in importance (ß = 11.46), and permissive parenting was fifth (ß = 9.2) in influencing academic performance of children in the study area. Children who experienced authoritative parenting and were from higher socioeconomic status families perform better as compared to children who experienced authoritarian and permissive parenting and were from low socioeconomic status families.


Academic Performance , Parenting , Humans , Child , Cross-Sectional Studies , Students , Social Class
12.
Opt Lett ; 48(20): 5253-5256, 2023 Oct 15.
Article En | MEDLINE | ID: mdl-37831840

In this Letter, a new, to the best of our knowledge, geometric shaping method for an ultrahigh-order 16384-ary quadrature amplitude modulation (16384QAM) constellation based on the delta-sigma modulation technique is proposed. Based on the characteristics of delta-sigma modulation, the constellation was optimized to obtain greater constellation gain and improve the maximum performance of the system. Finally, the proposed scheme was demonstrated on an intensity-modulated direct detection (IMDD) system through a 25 km single-mode fiber transmission. On performing experiments, it was found that the suggested approach increases the receiver sensitivity of ultrahigh-order QAM communication systems based on delta-sigma modulation by around 0.5 dB and further enhances the error performance limit.

13.
Opt Lett ; 48(17): 4548, 2023 Sep 01.
Article En | MEDLINE | ID: mdl-37656550

This publisher's note contains corrections to Opt. Lett.48, 4101 (2023)10.1364/OL.493540.

14.
Opt Express ; 31(19): 30130-30145, 2023 Sep 11.
Article En | MEDLINE | ID: mdl-37710562

This paper proposes a three-dimensional power sparse code division non-orthogonal multiple access (3D-PSCD-NOMA) scheme with 3D constellation pair mapping. The proposed sparse code is based on a balanced incomplete block design (BIBD). Its correlation matrix performs the overall signal mapping of multi-user information. Power multiplexing is realized by overlaying multi-level power signals with different path losses through pair mapping. Compared with the conventional 2D standard square 32 Quadrature Amplitude Modulation (QAM), the proposed 3D constellation pair mapping can improve the constellation points' minimum Euclidean distance (MED) by 17.7%, which is beneficial for the performance of the system. Based on obtaining the optimal power distribution ratio (PDR) for different schemes, a 3D-PSCD-NOMA signal with a rate of 15.22 Gb/s over a 25 km single-mode fiber (SMF) is experimentally performed. The experimental results show that 3D-PSCD-NOMA has a clear superiority. At the same rate, 3D-PSCD-NOMA2 can obtain a sensitivity gain of about 1.6 dB and 1.9 dB over the conventional 2D constellation. Moreover, 3D-PSCD-NOMA reduces the system's peak-to-average power ratio (PAPR) by 1.3 dB. The difference in sensitivity of the system before and after sparse code is about 0.15 dB, and no significant degradation occurred. Due to its advantages in transmission performance, 3D-PSCD-NOMA is a potential solution for future optical access systems.

15.
Opt Express ; 31(17): 27711-27722, 2023 Aug 14.
Article En | MEDLINE | ID: mdl-37710840

In this paper, we propose a multi-dimensional multiplexing scheme for space division multiplexing optical transmission systems based on quaternion chaotic encryption. A constellation compression shaping mapping method is designed to replace the traditional 2n mapping scheme, which leads to flexible encoding modulation. In order to achieve orthogonality between data symbols and effectively suppress crosstalk, the spectrally superposed transmission of three-dimensional (3D) constellation data is carried out by code division multiplexing and 4D carrier-less amplitude phase joint modulation techniques based on orthogonal basis. The Chen's chaotic model is utilized to generate the rotation angle of the constellation points, which enables data encryption without changing the transmitted power, enhancing system's security. The feasibility and superiority of the proposed scheme are successfully verified by constructing an experimental platform for a seven-core fiber transmission system.

16.
Opt Express ; 31(17): 28355-28369, 2023 Aug 14.
Article En | MEDLINE | ID: mdl-37710891

Constellation shaping (CS) has always been a popular research hotspot in optical communication. Recently, most researchers have focussed on using constellation-shaping technology to improve the system's performance, ignoring the additional penalty it brings to the coherent system. This paper proposes a method of constellation truncation using sub-constellation overlap to perform CS on quadrature amplitude modulation (QAM). The experimental results show that compared with the traditional probabilistic shaping 16QAM, the proposed scheme can effectively avoid the extra penalty brought by CS and achieve a gain from 0.5 to 1.5 dB in optical signal-to-noise ratio. To practically verify the proposed scheme's performance, 7-core 16 km fiber span is deployed in the field to experimentally perform space division multiplexed coherent transmission. The wavelength division multiplexing (WDM) of 93 carriers was used to achieve coherent transmission at a net rate of 116.66-Tb/s.

17.
Exp Neurobiol ; 32(4): 216-246, 2023 Aug 31.
Article En | MEDLINE | ID: mdl-37749925

This review examines the role of impaired amyloid-ß clearance in the accumulation of amyloid-ß in the brain and the periphery, which is closely associated with Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). The molecular mechanism underlying amyloid-ß accumulation is largely unknown, but recent evidence suggests that impaired amyloid-ß clearance plays a critical role in its accumulation. The review provides an overview of recent research and proposes strategies for efficient amyloid-ß clearance in both the brain and periphery. The clearance of amyloid-ß can occur through enzymatic or non-enzymatic pathways in the brain, including neuronal and glial cells, blood-brain barrier, interstitial fluid bulk flow, perivascular drainage, and cerebrospinal fluid absorption-mediated pathways. In the periphery, various mechanisms, including peripheral organs, immunomodulation/immune cells, enzymes, amyloid-ß-binding proteins, and amyloid-ß-binding cells, are involved in amyloid-ß clearance. Although recent findings have shed light on amyloid-ß clearance in both regions, opportunities remain in areas where limited data is available. Therefore, future strategies that enhance amyloid-ß clearance in the brain and/or periphery, either through central or peripheral clearance approaches or in combination, are highly encouraged. These strategies will provide new insight into the disease pathogenesis at the molecular level and explore new targets for inhibiting amyloid-ß deposition, which is central to the pathogenesis of sporadic AD (amyloid-ß in parenchyma) and CAA (amyloid-ß in blood vessels).

18.
Opt Lett ; 48(15): 4101-4104, 2023 Aug 01.
Article En | MEDLINE | ID: mdl-37527128

This study aims to present a non-orthogonal multiple access (NOMA) security scheme based on constellation camouflage and selective mapping. To improve the security of the system, we use a four-dimensional chaos model to camouflage high-power signals at the transmitter. The constellation diagram of high power is disguised from binary phase-shift keying (BPSK) form to quadrature phase-shift keying (QPSK) form, and after power multiplexing, further camouflaged from 8 points to 16 points. To improve the transmission performance of the designed system as much as possible and not increase the computational complexity, we use the selective mapping method in the process of power multiplexing and use the region decision method for demodulation at the receiving end. The proposed scheme is verified by experiments on a 2-km 7-core optical fiber, and achieves the safety transmission of a power division multiplexing-orthogonal frequency-division multiplexing (PDM-OFDM) signal with a net rate of 97.38 Gb/s without signal damage. The maximum achievable key space of the proposed scheme is 10135. Hence, it is a feasible and secure non-orthogonal multiple access-passive optical network scheme.

19.
Opt Lett ; 48(16): 4205-4208, 2023 Aug 15.
Article En | MEDLINE | ID: mdl-37581993

In this Letter, we propose a highly secure three-dimensional orthogonal frequency division multiplexing (3D-OFDM) transmission scheme based on two-level noise masking key-accompanying transmission. The original signal is encrypted with a spherical constellation to ensure the system's security with a 4D Lorenz-like model. The key realizes two-level noise masking by introducing additional noise bits at the bit level and hiding in a noise-like spherical shell at the constellation level. Moreover, the proposed method of placing the key in the encrypted signal can simultaneously transmit the encrypted signal and the key. A 101.06-Gb/s 3D-OFDM encrypted signal with the proposed scheme over a 2-km 7-core fiber experiment was successfully implemented. Experimental results show that the security performance of the system can be guaranteed under the conditions of partial key leakage and key misplacement at the illegal receiver. At the same time, the key masking degree (KMD) of the proposed two-level noise masking can reach 3267, which effectively guarantees the safe transmission of the key.

20.
Opt Lett ; 48(16): 4408-4411, 2023 Aug 15.
Article En | MEDLINE | ID: mdl-37582044

In this paper, an artificial-intelligence-based secure semantic optical communication scheme is proposed. The semantic features of the original text information are extracted using Transformer. Compared with other networks, Transformer reduces the complexity of the structure and the associated training cost by using the multi-head attention mechanism. To solve the security problem, the encryption scheme is applied to an orthogonal frequency division multiplexed passive optical network (OFDM-PON). The proposed scheme applies chaotic sequences to produce masking vectors. We encrypt the constellation and frequency, achieving a large key space of 1 × 10270. To prove that Transformer can effectively extract the semantic features of text, we have computed the values of ROUGE-1, ROUGE-2, and ROUGE-L, which are 40.9, 18.02, and 37.17, respectively. An encrypted 16 quadrature amplitude modulation (16QAM) OFDM signal transmission over a 2 km seven-core fiber with a data rate of 78.5 Gbits/s was experimentally demonstrated. During the experiments, the bit error rate (BER) was analyzed and the results show that the proposed system improves efficiency and security in an OFDM-PON system.

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