• Title/Summary/Keyword: approximately continuous

Search Result 351, Processing Time 0.023 seconds

Discontinuous deformation analysis for reinforced concrete frames infilled with masonry walls

  • Chiou, Yaw-Jeng;Tzeng, Jyh-Cherng;Hwang, Shuenn-Chang
    • Structural Engineering and Mechanics
    • /
    • v.6 no.2
    • /
    • pp.201-215
    • /
    • 1998
  • The structural behavior of reinforced concrete frame infilled with a masonry wall is investigated by the method of discontinuous deformation analysis (DDA). An interface element is developed and it is incorporated into DDA to analyze the continuous and discontinuous behavior of the masonry structure. The numerical results are compared with previous research and possess satisfactory agreement. Then the structural behavior and stress distribution of a reinforced concrete frame infilled with a masonry wall subjected to a horizontal force are studied. In addition, the justification of equivalent strut is assessed by the distribution of principal stresses. The results show that the behavior of the masonry structure is highly influenced by the failure of mortar. On the basis of the distribution of principal stress of the masonry wall in the reinforced concrete frame, the equivalent strut can be approximately substituted for the masonry wall without separation and opening. However, the application of equivalent strut to the masonry wall with separation and opening needs further study.

Dimming Control of LED Light Using Pulse Frequency Modulation in Visible Light Communication

  • Lee, Seong-Ho
    • Journal of information and communication convergence engineering
    • /
    • v.19 no.4
    • /
    • pp.269-275
    • /
    • 2021
  • Light-emitting diodes (LEDs) are modulated using a square wave pulse sequence for flicker prevention and dimming control in visible light communication (VLC). In a VLC transmitter, the high and low bits of the non-return-to-zero (NRZ) data are converted to two square waves of different frequencies, which continue for a finite time defined by the fill ratio in an NRZ bit time. As the average optical power was kept constant and independent of data transmission, the LED was flicker-free. Dimming control is carried out by changing the fill ratio of the square wave in the NRZ bit time. In the experiments, the illumination of the LED light was controlled in the range of approximately 19.2% to 96.2% of the continuous square wave modulated LED light. In the VLC receiver, a high-pass filter combined with a latch circuit was used to recover the transmitted signal while preventing noise interference from adjacent lighting lamps.

Review of the Clinical Practice Guidelines for Irritable Bowel Syndrome in Korea, 2017 Revised Edition (2017 과민성장증후군의 임상진료지침 개정안 소개)

  • Jung, Hye-Kyung
    • The Korean Journal of Gastroenterology
    • /
    • v.72 no.5
    • /
    • pp.252-257
    • /
    • 2018
  • This guidance is an updated version of the irritable bowel syndrome (IBS) guidelines based on evidence-based medicine. IBS is a common chronic gastrointestinal syndrome that occurs in approximately 10% of the population and causes chronic abdominal pain as well as bowel habit changes, such as stool frequency or consistency. The final diagnosis of IBS is based on the exclusion of organic diseases that would explain the symptoms and the absence of endoscopic abnormalities. IBS can reduce the quality of life and cause a major disease burden, such as repeated examinations and continuous drug use, by mistaking organic diseases including malignancy. The major changes are as follows: 1) when to perform a colonoscopy under the impression of IBS; 2) effect of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyol diet; 3) impact of probiotics in IBS; and 4) role of antibiotics in IBS. The Korean Society of Neurogastroenterology and Motility recently updated these guidelines to support physicians for qualified medical services and reduce the socioeconomic burden of IBS.

Excitation and Emission Properties of Adsorbed U(VI) on Amorphous Silica Surface

  • Jung, Euo Chang;Kim, Tae-Hyeong;Kim, Hee-Kyung;Cho, Hye-Ryun;Cha, Wansik
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.18 no.4
    • /
    • pp.497-508
    • /
    • 2020
  • In the geochemical field, the chemical speciation of hexavalent uranium (U(VI)) has been widely investigated by performing measurements to determine its luminescence properties, namely the excitation, emission, and lifetime. Of these properties, the excitation has been relatively overlooked in most time-resolved laser fluorescence spectroscopy (TRLFS) studies. In this study, TRLFS and continuous-wave excitation-emission matrix spectroscopy are adopted to characterize the excitation properties of U(VI) surface species that interact with amorphous silica. The luminescence spectra of U(VI) measured from a silica suspension and silica sediment showed very similar spectral shapes with similar lifetime values. In contrast, the excitation spectra of U(VI) measured from these samples were significantly different. The results show that distinctive excitation maxima appeared at approximately 220 and 280 nm for the silica suspension and silica sediment, respectively.

A Hybrid PSO-BPSO Based Kernel Extreme Learning Machine Model for Intrusion Detection

  • Shen, Yanping;Zheng, Kangfeng;Wu, Chunhua
    • Journal of Information Processing Systems
    • /
    • v.18 no.1
    • /
    • pp.146-158
    • /
    • 2022
  • With the success of the digital economy and the rapid development of its technology, network security has received increasing attention. Intrusion detection technology has always been a focus and hotspot of research. A hybrid model that combines particle swarm optimization (PSO) and kernel extreme learning machine (KELM) is presented in this work. Continuous-valued PSO and binary PSO (BPSO) are adopted together to determine the parameter combination and the feature subset. A fitness function based on the detection rate and the number of selected features is proposed. The results show that the method can simultaneously determine the parameter values and select features. Furthermore, competitive or better accuracy can be obtained using approximately one quarter of the raw input features. Experiments proved that our method is slightly better than the genetic algorithm-based KELM model.

Uncertainty analysis of speed-power performance based on measured raw data in sea trials

  • Seo, Dae-Won;Oh, Jungkeun
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.13 no.1
    • /
    • pp.396-404
    • /
    • 2021
  • It is important to verify that the contracted speed-power performance of a ship is satisfied in sea trials. International Organization for Standardization (ISO) has published the procedure for measuring and assessing ship speed during sea trials. The results obtained from actual sea conditions inevitably include various uncertainty factors. In this study, double run tests were performed on one container ship to analyze the uncertainty of sea trial on three maximum continuous rating conditions. The uncertainty factors and scale of uncertainty were examined based on the measured raw data during sea trial. The results indicate that the expanded uncertainty for ideal power performance is approximately ±1.4% at 95% confidence level (coverage factor k = 2) and most of the uncertainty factors were because of the shaft power measurement system.

SILICON DIOXIDE FILMS FOR INTERMETAL DIELECTRIC APPLICATIONS DEPOSITED BY AN ECR HIGH DENSITY PLASMA SYSTEM

  • Denison, D.R.;Harshbarger, W.R.
    • Journal of the Korean Vacuum Society
    • /
    • v.4 no.S1
    • /
    • pp.130-137
    • /
    • 1995
  • Deopsition of thermal quality SiO2 using a high density plasma ECR CVD process has been demonstrated to give void and seam free gap fill of high aspect ratio metallization structures with a simple oxygen-silane chemistry. This is achieved by continuous sputter etching of the film during the deposition process. A two-step process is utilized to deposit a composite layer for higher manufacturing efficiency. The first step, which has a deposition rate of approximately 0.5 $\mu$m/min., is used to provide complete gap fill between the metal lines. The second step, which has a deposition rate of up to 1.5 $\mu$m/min., is used to deposit a total thickness of 2.0$\mu$m for the intermetal dielectric film. The topography of this composite film is very compatible with subsequent chemicl mechanical polishing(CMP) planarization processing.

  • PDF

Immunological Mechanisms in Cutaneous Adverse Drug Reactions

  • Ai-Young Lee
    • Biomolecules & Therapeutics
    • /
    • v.32 no.1
    • /
    • pp.1-12
    • /
    • 2024
  • Adverse drug reactions (ADRs) are an inherent aspect of drug use. While approximately 80% of ADRs are predictable, immune system-mediated ADRs, often unpredictable, are a noteworthy subset. Skin-related ADRs, in particular, are frequently unpredictable. However, the wide spectrum of skin manifestations poses a formidable diagnostic challenge. Comprehending the pathomechanisms underlying ADRs is essential for accurate diagnosis and effective management. The skin, being an active immune organ, plays a pivotal role in ADRs, although the precise cutaneous immunological mechanisms remain elusive. Fortunately, clinical manifestations of skin-related ADRs, irrespective of their severity, are frequently rooted in immunological processes. A comprehensive grasp of ADR morphology can aid in diagnosis. With the continuous development of new pharmaceuticals, it is noteworthy that certain drugs including immune checkpoint inhibitors have gained notoriety for their association with ADRs. This paper offers an overview of immunological mechanisms involved in cutaneous ADRs with a focus on clinical features and frequently implicated drugs.

Production of Trans-10, Cis-12 Conjugated Linoleic Acid by Megasphaera Elsdenii YJ-4: Physiological Roles in the Rumen

  • Kim, T.W.;Choi, N.J.;Hwangbo, J.;Hsu, Jih-Tay;Lee, Sang S.;Song, M.K.;Seo, I.J.;Kim, Y.J.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.18 no.10
    • /
    • pp.1425-1429
    • /
    • 2005
  • Megaspahera elsdenii YJ-4, which was previously isolated as a producer of trans-10, cis-12 CLA, was studied for its carbon source on the CLA production. M. elsdenii YJ-4, was incubated with glucose and lactose, and cultured in batch and continuous culture systems with linoleic acid at various pHs to investigate CLA production. Batch cultures of the ruminal bacterium, M. elsdenii YJ-4, were resistant to stearic acid and linoleic acid, and little growth inhibition was observed even when the fatty acid concentration in the culture was as much as 4 mg $ml^{-1}$. Stationary phase batch cultures (0.25 mg bacterial protein $ml^{-1}$) that had been grown on lactate and incubated with linoleic acid (0.20 mg $ml^{-1}$) produced approximately 12 ${\mu}g$ trans-10, cis-12 CLA mg $protein^{-1}$ and little cis-9, trans-11 CLA was detected. Some linoleic acid was converted to hydrogenated products (chiefly stearic acid), but these fatty acids were less than 5 ${\mu}g$ mg bacterial $protein^{-1}$. Stationary phase batch cultures that had been grown on glucose produced at least 3-fold less trans-10, cis-12 CLA than ones grown on lactate. Cells from lactate-limited continuous cultures produced less trans-10, cis-12 CLA than those from batch culture, but only if the pH was greater than 6.4. When the pH of the lactate-limited continuous cultures was lower than 6.4, trans-10, cis-12 CLA and hydrogenated products declined. Cells from glucose-limited continuous cultures produced less trans-10, cis-12 CLA and hydrogenated products than the cells that had been limited by lactate, but pH had little impact on this production. These results support the idea that M. elsdenii YJ-4 could be one of the major producers of trans-10, cis-12 CLA which causes cows to produce milk with a low fat content.

Evaluation of Grid-Based ROI Extraction Method Using a Seamless Digital Map (연속수치지형도를 활용한 격자기준 관심 지역 추출기법의 평가)

  • Jeong, Jong-Chul
    • Journal of Cadastre & Land InformatiX
    • /
    • v.49 no.1
    • /
    • pp.103-112
    • /
    • 2019
  • Extraction of region of interest for satellite image classification is one of the important techniques for efficient management of the national land space. However, recent studies on satellite image classification often depend on the information of the selected image in selecting the region of interest. This study propose an effective method of selecting the area of interest using the continuous digital topographic map constructed from high resolution images. The spatial information used in this research is based on the digital topographic map from 2013 to 2017 provided by the National Geographical Information Institute and the 2015 Sejong City land cover map provided by the Ministry of Environment. To verify the accuracy of the extracted area of interest, KOMPSAT-3A satellite images were used which taken on October 28, 2018 and July 7, 2018. The baseline samples for 2015 were extracted using the unchanged area of the continuous digital topographic map for 2013-2015 and the land cover map for 2015, and also extracted the baseline samples in 2018 using the unchanged area of the continuous digital topographic map for 2015-2017 and the land cover map for 2015. The redundant areas that occurred when merging continuous digital topographic maps and land cover maps were removed to prevent confusion of data. Finally, the checkpoints are generated within the region of interest, and the accuracy of the region of interest extracted from the K3A satellite images and the error matrix in 2015 and 2018 is shown, and the accuracy is approximately 93% and 72%, respectively. The accuracy of the region of interest can be used as a region of interest, and the misclassified region can be used as a reference for change detection.