• Title/Summary/Keyword: Time-variant

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A Novel Framework Based on CNN-LSTM Neural Network for Prediction of Missing Values in Electricity Consumption Time-Series Datasets

  • Hussain, Syed Nazir;Aziz, Azlan Abd;Hossen, Md. Jakir;Aziz, Nor Azlina Ab;Murthy, G. Ramana;Mustakim, Fajaruddin Bin
    • Journal of Information Processing Systems
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    • v.18 no.1
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    • pp.115-129
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    • 2022
  • Adopting Internet of Things (IoT)-based technologies in smart homes helps users analyze home appliances electricity consumption for better overall cost monitoring. The IoT application like smart home system (SHS) could suffer from large missing values gaps due to several factors such as security attacks, sensor faults, or connection errors. In this paper, a novel framework has been proposed to predict large gaps of missing values from the SHS home appliances electricity consumption time-series datasets. The framework follows a series of steps to detect, predict and reconstruct the input time-series datasets of missing values. A hybrid convolutional neural network-long short term memory (CNN-LSTM) neural network used to forecast large missing values gaps. A comparative experiment has been conducted to evaluate the performance of hybrid CNN-LSTM with its single variant CNN and LSTM in forecasting missing values. The experimental results indicate a performance superiority of the CNN-LSTM model over the single CNN and LSTM neural networks.

A three-dimensional two-hemisphere model for unmanned aerial vehicle multiple-input multiple-output channels

  • Zixu Su;Wei Chen;Changzhen Li;Junyi Yu;Guojiao Gong;Zixin Wang
    • ETRI Journal
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    • v.45 no.5
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    • pp.768-780
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    • 2023
  • The application of unmanned aerial vehicles (UAVs) has recently attracted considerable interest in various areas. A three-dimensional multiple-input multiple-output concentric two-hemisphere model is proposed to characterize the scattering environment around a vehicle in an urban UAV-to-vehicle communication scenario. Multipath components of the model consisted of lineof-sight and single-bounced components. This study focused on the key parameters that determine the scatterer distribution. A time-variant process was used to analyze the nonstationarity of the proposed model. Vital statistical properties, such as the space-time-frequency correlation function, Doppler power spectral density, level-crossing rate, average fade duration, and channel capacity, were derived and analyzed. The results indicated that with an increase in the maximum scatter radius, the time correlation and level-crossing rate decreased, the frequency correlation function had a faster downward trend, and average fade duration increased. In addition, with the increase of concentration parameter, the time correlation, space correlation, and level-crossing rate increased, average fade duration decreased, and Doppler power spectral density became flatter. The proposed model was compared with current geometry-based stochastic models (GBSMs) and showed good consistency. In addition, we verified the nonstationarity in the temporal and spatial domains of the proposed model. These conclusions can be used as references in the design of more reasonable communication systems.

COVID-19 Surveillance using Wastewater-based Epidemiology in Ulsan (울산지역 하수기반역학을 이용한 코로나19 감시 연구)

  • Gyeongnam Kim;Jaesun Choi;Yeon-Su Lee;Dae-Kyo Kim;Junyoung Park;Young-Min Kim;Youngsun Choi
    • Journal of Food Hygiene and Safety
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    • v.39 no.3
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    • pp.260-265
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    • 2024
  • During the coronavirus 2019 (COVID-19) pandemic, wastewater-based epidemiology was used for surveying infectious diseases. In this study, wastewater surveillance was employed to monitor COVID-19 outbreaks. Wastewater influent samples were collected from four sewage treatment plants in Ulsan (Gulhwa, Yongyeon, Nongso, and Bangeojin) between August 2022 and August 2023. The samples were concentrated using the polyethylene glycol-sodium chloride pretreatment method. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was extracted and detected using real-time polymerase chain reaction. Next generation sequences was used to perform correlation analysis between SARS-CoV-2 concentrations and COVID-19 cases and for COVID-19 variant analysis. A strong correlation was observed between SARS-CoV-2 concentrations and COVID-19 cases (correlation coefficient, r = 0.914). The COVID-19 variant analysis results were similar to the clinical variant genomes of three epidemics during the study period. In conclusion, monitoring COVID-19 via analyzing wastewater facilitates early recognition and prediction of epidemics.

Genetic characterization of methicillin-resistant Staphylococcus aureus from humans and animals within the community (지역사회 내 일반인 및 동물에서 methicillin 내성 Staphylococcus aureus의 유전학적 특성)

  • Cho, Jae-Keun;Kim, Jin-Hyun;Sung, Myung-Suk;Kim, Ki-Seuk
    • Korean Journal of Veterinary Research
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    • v.51 no.4
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    • pp.267-275
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    • 2011
  • Methicillin-resistant Staphylococcus (S.) aureus (MRSA) is one of the most important nosocomial pathogens worldwide and the emergence of this strain has become a major clinical problem. In this study, we investigated the prevalence of MRSA and their genetic characteristics in 69 S. aureus isolated from humans and animals. In human isolates, higher antimicrobial resistance rates were observed against penicillin (80.6%), followed by erythromycin (11.9%) and tetracycline (9.0%). All of them were susceptible to clindamycin, enrofloxacin, novobiocin, pirlimycin, trimethoprim/sulfamethoxazole and vancomycin. The resistance patterns in animal isolates were similar to those of human isolates. Two (2.9%) MRSA strains were isolated from human (n = 1) and animal (n = 1), and these isolates were confirmed as carrying the mecA gene. One isolate originating from human was resistant to 7 drugs and the other isolate derived from animal was resistant to 11 drugs. Staphylococcal cassette chromosome mec (SCCmec) variant IIIB was identified in animal isolate but SCCmec type of an isolate from human was not exactly determined. Two MRSA isolates showed unrelated PFGE pattern between them. Our results indicated although the frequency of MRSA isolates from humans and animals was low, a continuous surveillance and monitoring should be called for to prevent the contamination and spread of MRSA in the community. To our knowledge, this is the first time that SCCmec type variant IIIB was detected from animals in Korea.

Modified Orbitozygomatic Approach without Orbital Roof Removal for Middle Fossa Lesions

  • Lopez-Elizalde, Ramiro;Robledo-Moreno, Edgar;O'Shea-Cuevas, Gabriel;Matute-Villasenor, Esmeralda;Campero, Alvaro;Godinez-Rubi, Marisol
    • Journal of Korean Neurosurgical Society
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    • v.61 no.3
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    • pp.407-414
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    • 2018
  • Objective : The purpose of the present study was to describe an OrBitoZygomatic (OBZ) surgical variant that implies the drilling of the orbital roof and lateral wall of the orbit without orbitotomy. Methods : Design : cross-sectional study. Between January 2010 and December 2014, 18 patients with middle fossa lesions underwent the previously mentioned OBZ surgical variant. Gender, age, histopathological diagnosis, complications, and percentage of resection were registered. The detailed surgical technique is described. Results : Of the 18 cases listed in the study, nine were males and nine females. Seventeen cases (94.5%) were diagnosed as primary tumoral lesions, one case (5.5%) presented with metastasis of a carcinoma, and an additional one had a fibrous dysplasia. Age ranged between 27 and 73 years. Early complications were developed in four cases, but all of these were completely resolved. None developed enophthalmos. Conclusion : The present study illustrates a novel surgical OBZ approach that allows for the performance of a simpler and faster procedure with fewer complications, and without increasing surgical time or cerebral manipulation, for reaching lesions of the middle fossa. Thorough knowledge of the anatomy and surgical technique is essential for successful completion of the procedure.

Association of lnc-LAMC2-1:1 rs2147578 and CASC8 rs10505477 Polymorphisms with Risk of Childhood Acute Lymphoblastic Leukemia

  • Hashemi, Mohammad;Bahari, Gholamreza;Naderi, Majid;Bojd, Simin Sadeghi;Taheri, Mohsen
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.4985-4989
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    • 2016
  • Long non-coding RNAs (lncRNAs) are a novel class of non-protein coding RNAs that are involved in a wide variety of biological processes. There are limited data regarding the impact of lnc-LAMC2-1:1 rs2147578 as well as CASC8 rs10505477 T>C polymorphisms on cancer development. Here we examined for the first time whether rs2147578 and rs10505477 polymorphisms are associated with childhood acute lymphoblastic leukemia (ALL) in a total of 110 cases and 120 healthy controls. Genotyping was achieved by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The rs2147578 variant increased the risk of ALL in codominant (OR=4.33, 95%CI=2.00-9.37, p<0.0001, CG vs CC, and OR=5.81, 95%CI=2.30-14.69, p=0.0002, GG vs CC), dominant (OR=4.63, 95%CI=2.18-9.86, p<0.0001, CG+GG vs CC), overdominant (OR=1.74, 95%CI=1.02-2.97, p=0.0444, CG vs CC+GG) and allele (OR=1.91, 95%CI=1.32-2.77, p=0.0008, G vs C) inheritance models tested. No significant association was found between the CASC8 rs10505477 T>C variant and risk of childhood ALL. In conclusion, the present study revealed that the lnc-LAMC2-1:1 rs2147578 polymorphism may be a risk factor for developing childhood ALL. Further studies with larger sample sizes with different ethnicities are now required to confirm our findings.

Control Law Design for a Tilt-rotor Unmanned Aerial Vehicle with a Nacelle Mounted WE (Wing Extension) (체공성능 향상을 위한 확장날개 틸트로터 무인기의 제어법칙설계)

  • Kang, Young-Shin;Park, Bum-Jin;Cho, Am;Yoo, Chang-Sun
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.11
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    • pp.1103-1111
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    • 2014
  • The results of control law design for a tilt-rotor unmanned aerial vehicle that has a nacelle mounted wing extension (WE) are presented in this paper. It consists of a control surface mixer, stability and control augmentation system (SCAS), hold mode for altitude / speed / heading, and a guidance mode for preprogram and point navigation which includes automatic take-off and landing. The conversion corridor and the control moments derivatives between the original tilt-rotor and its variant of the nacelle mounted WE were compared to show the effectiveness of the WE. The nacelle conversion of the original tilt-rotor starts when the airspeed is greater than 30 km/h but its WE variant starts at 0 km/h in order to reduce the drag caused by the high incidence angle of the WE. The stability margins of the inner loop are presented with the optimization approach. The outer loops for the hold mode are designed with trial and error methods with linear and nonlinear simulation. The main control parameter for altitude control of the helicopter mode is thrust command and it is transferred to the pitch attitude command in airplane mode. Otherwise, the control parameter for the speed of the helicopter mode is the pitch attitude command and it is transferred to the thrust command in airplane mode. Therefore the speed and altitude hold mode are coupled to each other and are engaged at the same time when an internal pilot engages any of the altitude or speed hold modes. The nonlinear simulation results of the guidance control for the preprogrammed mode and point navigation are also presented including automatic take-off and landing in order to prove the full control law.

XRCC1 Polymorphisms are Associated with Cervical Cancer Risk and Response to Chemotherapy: a Systematic Review and Meta-analysis

  • Shuai, Han-Lin;Luo, Xin;Yan, Rui-Ling;Li, Jian;Chen, Dan-Liang
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6423-6427
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    • 2012
  • Background: Functional single nucleotide polymorphisms of x-ray repair cross-complementing protein 1 (XRCC1) have been suspected to contribute to uterine cervical cancer risk for a long time; however, most previous case-control studies were small sized and biased. Additionally, recent studies suggested that XRCC1 polymorphisms could be a biomarker of response to platinum-based chemotherapy. Methods: A comprehensive search was conducted to retrieve eligible studies and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to measure association strength. Results: A total of 13 studies were identified and analyzed. We found that the Arg194Trp polymorphism (Trp vs. Arg, OR=1.342, 95% CI: 1.176) was associated with increased risk of cervical cancer, while no significant association was found with Arg280His (His vs. Arg, OR=1.059, 95% CI: 0.863, 1.299) or Arg399Gln (Gln vs. Arg, OR=1.144, 95% CI: 0.938, 1.394). As for response to platinum-based chemotherapy, the variant XRCC1 399Gln allele (Gln vs. Arg, OR=0.345, 95% CI: 0.163, 0.729) was linked with a poor response; however, the Arg194Trp polymorphism (TrpArg vs. ArgArg, OR=6.421, 95% CI: 1.573, 26.205) predicted a good response. Conclusion: The Arg194Trp polymorphism of XRCC1 increases risk of cervical cancer; the variant 399Gln allele predicts poor response to platinum-based chemotherapy, while the Arg194Trp polymorphism indicates a good response.

Long Term Follow-Up of Cyclic Vomiting Syndrome (주기성 구토증(cyclic vomiting syndrome)의 장기 추적 관찰 -이형 편두통(migraine variant)으로의 이행 과정인가?-)

  • Hwang, Jin-Bok;Oh, Hee-Jong;Choi, Kwang-Hae
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.3 no.1
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    • pp.75-83
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    • 2000
  • Cyclic vomiting syndrome(CVS) is a disorder of unknown etiology that is characterized by its clinical pattern of intermittent episodes of severe vomiting, similar in time of onset and duration, with no symptoms during the intervening period. By definition, CVS is an idiopathic disorder that requires exclusionary laboratory testing. Not only can it be mimicked by many specific disorders, eg, surgical, neurologic, endocrine, metabolic, renal, but within idiopathic CVS there may be specific subgroups that have different mechanisms. It has been reported that CVS usually begins in toddlers and resolves during adolescence. Migraine is also self-limiting episodic condition of children and the clinical features of migraine and CVS show considerable similarity. It is proposed that CVS is a condition related to migraine. This paper reports clinical courses of long term follow-up and reversible EEG changes in three patients whose history included CVS. Clinical situations of attack interval, duration and associated symptoms had changed variablely in each patients through long term follow-up period. Cyclic vomiting subsided in two cases. Abnormal delta activity was seen during episodes and resolved at follow-up, when the patient asymptomatic. The brain wave changes support the interpretation of CVS as a migraine variant.

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Pathophysiology of orthostatic tremor: a multiple case study (길입성 진전의 병태생리: 다증 증례 연구)

  • Seo, Man-Wook;Lee, Kwang-Woo
    • Annals of Clinical Neurophysiology
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    • v.4 no.1
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    • pp.44-50
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    • 2002
  • Introduction : Orthostatic tremor develops in the legs while standing up with no weakness, pain or imbalance in the leg and the tremor is characteristically not observed when walking. However there have been some confusions about orthostatic tremor in several aspects. For the past ten years, we have observed 4 patients with orthostatic tremor. In each case tests were performed to investigate the following three important areas of inquiry about orthostatic tremor. Firstly, whether this disorder is an independent diagnostic entity or a variant of essential tremor. Secondly, whether the progress of this disorder is specifically related with standing posture. Lastly, the nature of the pathophysiologic mechanism behind the appearance of the tremor when standing after the lapse of a certain latent period and its disappearance upon the commencement of walking. Methods : Our 4 cases of orthostatic tremor were studied clinically, electrophysiologically, and pharmacologically. Electrophysiological tests included tremor spectrum test and electromyography. Results : We observed the presence of this tremor in several other tonic postures, as well as its absence, in a vertically lifted position from all our cases. Our cases registered a variable tremor frequency between 5 and 12 Hz according to the tremor spectrum test and EMG. Furthermore all our 4 cases demonstrated patterns of both synchronous EMG activity and alternating EMG activity at various times in homologous muscles of both legs. Orthostatic tremor was improved significantly with propranolol as well as clonazepam. Conclusions : From the results of our study we drew the following conclusions. It is probable that orthostatic tremor is simply a variant of essential tremor rather than being an independent diagnostic entity and that in most cases its development is specifically related with muscle contraction rather than merely with the act of standing. Furthermore we discovered a clue in the previously described neural control mechanism that the nuclear bag fibers in the muscle spindle have lag time of several seconds in their response to muscle strength and that their baseline does not reset fully in rapidly moving muscle. This neural control mechanism could offer sufficient explanation for the phenomena of tremor appearance when standing and disappearance when walking in orthostatic tremor.

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