• Title/Summary/Keyword: Life testing

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Prediction Model for Health-Related Quality of Life in Hospitalized Patients with Pulmonary Tuberculosis (폐결핵 입원환자의 건강관련 삶의 질 예측모형)

  • Jang, Kwang-Sim;Jeon, Gyeong-Suk
    • Journal of Korean Academy of Nursing
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    • v.47 no.1
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    • pp.60-70
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    • 2017
  • Purpose: This study was conducted to construct and test a structural equation model of health-related quality of life (HRQoL) among hospitalized patients with pulmonary tuberculosis (PTB). Methods: Participants were 256 patients with PTB who were 20 years or older and admitted in two national tuberculosis hospitals. The patients participated in pulmonary function testing and responded to structured questionaries. Results: The goodness-of-fit statistics of the final hypothetical model were as follows: ${\chi}^2/df=2.19$, RMSEA=.07, SRMR=.05, GFI=.95, NFI=.95, CFI=.96, TLI=.92, and PCFI=.52. Symptoms and general health perception had significant direct effects, and subjective economic status, social support and stigma had significant indirect effect on HRQoL of hospitalized patients with PTB. These variables explained 64% of variance in the prediction model. Conclusion: Findings suggest that strategies and intervention for physical symptoms and depressive symptoms are crucial to improve the quality of life in hospitalized patients with PTB. The development of various social support programs is also recommended.

Near-Isogenic Lines for Genes Conferring Hypersensitive Resistance to Bacterial Spot in Chili Pepper

  • Kim, Byung-Soo;Kim, Young-Chun;Shin, Kwang-Sik;Kim, Jeong-Hoon
    • The Plant Pathology Journal
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    • v.23 no.3
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    • pp.155-160
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    • 2007
  • In order to develop chili pepper bacterial spot resistant cultivars and near-isogenic lines (NILs) to prompt the molecular mapping of the resistance gene, we have run backcross breeding program since 1994. Two resistance genes against Xanthomonas axonopodis pv. vesicatoria Bs2 from Fla. XVR 3-25 and Bs3 from our breeding line 25-11-3-2, were introduced into a land race, Chilseongcho (abbreviated to Chilseong hereafter) with good fruit guality. We report here the testing of $BC_4F_3\;to\;BC_4F_5$. We found that $BC_4F_5$ lines of the crosses were homozygous with respect to the respective genes of introduction. The lines, in which Bs2 gene was introduced, were hypersensitively resistant to both race 1 and race 3 of X. axonopodis pv. vesicatoria, whereas, those in which Bs3 was introduced were resistant to race 1.

A study on the machinability of SUS304

  • Lim, K.Y.;Yu, K.H.;Seo, N.S.
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.1
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    • pp.34-41
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    • 1993
  • SUS304 is wellknown as difficult-to-machine materials. It is easy to appear workhardened, and workhardening is one of the causes of groove wear on the tool. In this paper, the author would like to compare the width of flank wear with that of groove wear, and to find whether the groove wear can be used as a criterion of a tool life. The design of the twelve tests provides three levels for each variable (speed: 200m/min, 118m/min, 70m/min; feed: 0.3mm/rev, 0.17mm/rev, 0.1mm/rev; depth of cut: 0.4mm, 0.28mm, 0.2mm). The study of tool-life testing by statistical technique follows usual most scientific sequence. So the tool-life predicting equation is calculated by the method of least squares. The overall adequacy of the model can be verified by the analysis of variance. The results obtained are as follows : 1) When SUS304 is cut in 200(m/min), the width of flank wear is much larger than that of groove wear. 2) In cutting speed 118m/min, flank wear is a little larger than groove wear and in the cutting speed 70m/min, the latter is a little larger so that it is reasonable to determine the tool life according the crierion by groove wear in the low cutting speed (less than 70m/min). 3) Owing to the burr the depth of engagement along the cutting edge is extended toward the shank.

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A Comparison of Reliability Factors of Software Reliability Model Following Lifetime Distribution Dependent on Pareto and Erlang Shape Parameters (파레토 및 어랑 형상모수에 의존한 수명분포를 따르는 소프트웨어 신뢰성 모형에 대한 신뢰도 특성요인 비교 연구)

  • Kim, Hee Cheul;Moon, Song Chul
    • Journal of Information Technology Applications and Management
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    • v.24 no.2
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    • pp.71-80
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    • 2017
  • Software reliability is one of the most elementary and important problems in software development In order to find the software failure occurrence, the instantaneous failure rate function in the Poisson process can have a constant, incremental or decreasing tendency independently of the failure time. In this study, we compared the reliability performance of the software reliability model using the parameters of Pareto life distribution with the intensity decreasing pattern and the shape parameter of Erlang life distribution with the intensity increasing and decreasing pattern in the software product testing. In order to identify the software failure environment, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, we compare and evaluate software reliability by applying software failure time data. The reliability of the Erlang and Pareto life models is shown to be higher than that of the Pareto lifetime distribution model when the shape parameter is higher and the Erlang model is more reliable when the shape parameter is higher. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing basic knowledge using software failure analysis.

Low-cycle fatigue in steel H-piles of integral bridges; a comparative study of experimental testing and finite element simulation

  • Karalar, Memduh;Dicleli, Murat
    • Steel and Composite Structures
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    • v.34 no.1
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    • pp.35-51
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    • 2020
  • Integral abutment bridges (IABs) are those bridges without expansion joints. A single row of steel H-piles (SHPs) is commonly used at the thin and stub abutments of IABs to form a flexible support system at the bridge ends to accommodate thermal-induced displacement of the bridge. Consequently, as the IAB expands and contracts due to temperature variations, the SHPs supporting the abutments are subjected to cyclic lateral (longitudinal) displacements, which may eventually lead to low-cycle fatigue (LCF) failure of the piles. In this paper, the potential of using finite element (FE) modeling techniques to estimate the LCF life of SHPs commonly used in IABs is investigated. For this purpose, first, experimental tests are conducted on several SHP specimens to determine their LCF life under thermal-induced cyclic flexural strains. In the experimental tests, the specimens are subjected to longitudinal displacements (or flexural strain cycles) with various amplitudes in the absence and presence of a typical axial load. Next, nonlinear FE models of the tested SHP specimens are developed using the computer program ANSYS to investigate the possibility of using such numerical models to predict the LCF life of SHPs commonly used in IABs. The comparison of FE analysis results with the experimental test results revealed that the FE analysis results are in close agreement with the experimental test results. Thus, FE modeling techniques similar to that used in this research study may be used to predict the LCF life of SHP commonly used in IABs.

Storage Life Evaluation of a Violet Smoke Hand Grenade(KM18) using Degradation Data (열화데이터를 이용한 자색 연막수류탄(KM18)의 저장수명 평가)

  • Chang, Il-Ho;Hong, Suk-Hwan;Jang, Hyun-Jeung;Son, Young-Kap
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.2
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    • pp.215-223
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    • 2012
  • A violet smoke hand grenade(KM18) is used to generate signals. The grenade is considered to fail when its smoke emission time is longer than the specified one so that its smoke concentration becomes lighter. Accelerated degradation test for the grenade was performed, and then failure in smoke emission time was reproduced from the test. Stress for the degradation test was selected as temperature/humidity from the pre-test results. Degraded data of emission time from the accelerated test were analyzed through applying a distibution-based degradation model. Then, Peck Model was applied to predict the storage life under field conditions. In addition, the predicted storage life was compared with that of ASRP(Ammunition Stockpile Reliability Program).

A Study on Optimum Cutting Conditions and Tool Life in Deep Hole Drilling for SM55C by BTA Drill (BTA드릴에 의한 SM55C의 심공가공시 최적절삭조건과 공구수명에 관한 연구)

  • 장성규;전언찬
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.9
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    • pp.43-49
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    • 1998
  • The deep hole drilling has an increasing demands because of its wide range applications and its good productivity. The BTA drills are capable of machining for having a large length to diameter ratio in single pass to higher degree of accuracy and surface finish. It's really necessary that the investigation for the deep hole drilling by the BTA drill because its required quality should be satisfied with single pass. This thesis deal with the experimental results obtained during single tube BTA system machining on SM55C steel for different machining conditions. The results of the investigation on the optimum cutting condition selecting and tool life reveals as follows. (1) The optimum cutting condition was cutting speed, V = 42 m/min and feed speed. F = 90 mm/min and the tool life was about 10 meters. (2) Surface roughness was $12\mum$ and the roundness was less using $16mum$single edge BTA drill in testing cutting condition.

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Deep learning framework for bovine iris segmentation

  • Heemoon Yoon;Mira Park;Hayoung Lee;Jisoon An;Taehyun Lee;Sang-Hee Lee
    • Journal of Animal Science and Technology
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    • v.66 no.1
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    • pp.167-177
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    • 2024
  • Iris segmentation is an initial step for identifying the biometrics of animals when establishing a traceability system for livestock. In this study, we propose a deep learning framework for pixel-wise segmentation of bovine iris with a minimized use of annotation labels utilizing the BovineAAEyes80 public dataset. The proposed image segmentation framework encompasses data collection, data preparation, data augmentation selection, training of 15 deep neural network (DNN) models with varying encoder backbones and segmentation decoder DNNs, and evaluation of the models using multiple metrics and graphical segmentation results. This framework aims to provide comprehensive and in-depth information on each model's training and testing outcomes to optimize bovine iris segmentation performance. In the experiment, U-Net with a VGG16 backbone was identified as the optimal combination of encoder and decoder models for the dataset, achieving an accuracy and dice coefficient score of 99.50% and 98.35%, respectively. Notably, the selected model accurately segmented even corrupted images without proper annotation data. This study contributes to the advancement of iris segmentation and the establishment of a reliable DNN training framework.

Protection against spring viremia carp virus (SVCV) by immunization with chimeric snakehead rhabdovirus expressing SVCV G protein

  • Mariem Bessaid;Kyung Min Lee;Jae Young Kim;Ki Hong Kim
    • Journal of fish pathology
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    • v.37 no.1
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    • pp.17-23
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    • 2024
  • Spring viremia of carp virus (SVCV) poses a significant threat to numerous cyprinid fish species, particularly the common carp (Cyprinus carpio), often resulting in substantial mortalities. This study explores the potential use of a chimeric recombinant snakehead rhabdovirus carrying the SVCV G gene (rSHRV-Gsvcv) as a live vaccine against SVCV infection. Through virulence testing in zebrafish at different temperatures (15 ℃ and 20 ℃), no mortality was observed in groups infected with either rSHRV-wild or chimeric rSHRV-Gsvcv at both temperatures, whereas 100% mortality occurred in fish infected with wild-type SVCV. Subsequently, as no mortality was observed by rSHRV-Gsvcv, three independent experiments were conducted to determine the possible usage of chimeric rSHRV-Gsvcv as a vaccine candidate against SVCV infection. Fish were immunized with either rSHRV-Gsvcv or rSHRV-wild, and their survival rates against the SVCV challenge were compared with a control group injected with buffer alone at four weeks post-immunization. The results showed that chimeric rSHRV-Gsvcv induced significantly higher fish survival rates compared to rSHRV-wild and the control groups. These findings suggest that genetically engineered chimeric rSHRV-Gsvcv holds the potential for a prophylactic measure to protect fish against SVCV infection.

On Estimating the Hazard Rate for Samples from Weighted Distributions

  • Ahmad, Ibrahim A.
    • International Journal of Reliability and Applications
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    • v.1 no.2
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    • pp.133-143
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    • 2000
  • Data from weighted distributions appear, among other situations, when some of the data are missing or are damaged, a case that is important in reliability and life testing. The kernel method for hazard rate estimation is discussed for these data where the basic large sample properties are given. As a by product, the basic properties of the kernel estimate of the distribution function for data from weighted distribution are presented.

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