• Title/Summary/Keyword: Reliability standard

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A Study on the Standardization of Fineness Measurement for the Thermal Insulator of Military Textiles (방한용 화섬솜의 섬도 측정방법의 표준화에 관한 연구)

  • Hong, Seong-don;Kim, Byung-soon
    • Journal of Korean Society for Quality Management
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    • v.43 no.3
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    • pp.253-272
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    • 2015
  • Purpose: The purpose of this study is to enhance the reliability of quality inspection by standardize the fineness test method of the thermal insulator of military textiles Methods: We have measured the thermal insulator of military textiles by microscope with three different ways and the effectiveness of their difference were analyzed by one-way layout design. Results: We have suggest the standardized the fineness test method of the thermal insulator of military textiles through advanced research. As a result we have verified hollow ratio of heat insulating fiber affect fineness test methods. The fineness test method for the thermal insulator applied with different methods following hollow ratio. We have verified that when the hollow ratio over 90%, the fineness of the thermal insulator measured from fiber-length, if it has over 80%, the cross-section length of hollow and if it has less 80%, the cross-section area of hollow is applied, respectively. Conclusion: This study indicated that the test method of fineness shows high reliability. Heat insulating fibers which have high evenness shows narrow variations(5/% or less, only CV 25%) irrespectively under different testing equipment or institute. Based ons the results, we have suggest the standardization of test methods for fineness by microscope method and produced the registration of Group Standard in Korean Standards Association.

The Study of Asymmetrical of the Serratus Anterior and Lower Trapezius Muscles in Chronic Stroke Patients (만성 뇌졸중 환자의 앞 톱니근과 하부 등세모근의 비대칭성 연구)

  • Jeong, Ju-Ri;Lee, Wan-Hee
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.4
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    • pp.81-90
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    • 2015
  • PURPOSE: The purpose of this study was to compare the muscle architecture of serratus anterior and lower trapezius using rehabilitative ultrasound imaging (RUSI) in affected and unaffected side of chronic stroke patients. METHODS: The participants were thirty five patients with stroke hemiplegia in this study. RUSI was used to measure the muscle thickness of the serratus anterior and lower trapezius muscles. We compared the muscle thickness according to affected side and sex, determined the reliability of the measurement image. Independent t-test, intra-class correlation coefficient (ICC) and standard error of measurement (SEM) were used for statistical analysis. RESULTS: Significant difference in muscle thickness of serratus anterior was observed between affected and unaffected side (p<.001). Muscle thickness according to gender showed a significant difference in unaffected side of serratus anterior (p<.05). Compare asymmetry ratio of serratus anterior and lower trapezius muscle thickness showed a significant difference (p<.001). ICC for intra-reliability was .944~.962 in serratus anterior and .873~.925 in lower trapezius muscle thickness, respectively. SEM was .001~.004 in serratus anterior and .002~.008 in lower trapezius muscle. CONCLUSION: This study, using RUSI, showed significant difference in muscle thickness of serratus anterior in affected and unaffected side of stroke patients. RUSI is a practical tool for measuring soft-tissue thickness in the scapular region muscle of stroke.

Characteristic Measurement for Ready-Deployed Optical Cable and Simulation for SDH and WDM System Existing Conditions (기포설된 광케이블 특성측정과 이 선로조건에 대한 SDH 및 DWDM 광전송장치 전송특성측정과 시뮬레이션)

  • 이성원;김영범
    • Journal of Applied Reliability
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    • v.1 no.2
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    • pp.121-138
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    • 2001
  • Due to large demand for high speed and great capacity for data transfer, WDM, which uses the wavelength division multiplexing technique, is known as alternative way to satisfy those demand for its flexible network operation and management, easy network expansion with existing networks, and enhancement of efficient data transfer rate. For these reasons, a new high capacity WDM optical communication network plan was established. Therefore, the quality of currently deployed optical cables with 81.6 km in length should be assessed to ensure if high capacity WDM system could be implemented on existing optical cables. Two important characteristic parameters, Transfer Loss and PMD (Polarization Mode Dispersion), were measured to evaluate quality of existing optical cable. Transfer Loss was measured at 0.244 dB per kilometer, which is lower than the design standard value at 0.275 dB/km. The measured PMD value gave at 0.030ps/km, and it, therefore, satisfies the value recommended by ITU-T (International Telecommunication Union-T) of 0.5ps/km. In addition, the transfer characteristic for existing 2.5 Gbps and 10 Gbps system were measured and evaluated, and the results showed that error-free transfer is very much feasible. Computer simulation for DWDM system, which is likely be a future backbone network in Korea, to assess the transfer characteristic using the same condition employed for 2.5 Gbps and 10 Gbps was carried out as well. The simulation verified that a stable network operation and reliable service could be provided.

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Relationship between Green Consumer Behavior, Environmental Knowledge, and Environmental Attitudes among Students at the University of Education (교육대학교 재학생의 녹색소비자행동과 환경지식 및 환경태도의 관계)

  • Keum, Jiheon
    • Journal of the Korean Home Economics Association
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    • v.51 no.1
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    • pp.89-95
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    • 2013
  • The purpose of this study is to identify a causal relationship among green consumer behavior, environmental knowledge and environmental attitudes of students at the university of education. A total of 366 copies of questionnaires were used for the data analysis; 31 copies were excluded due to lack of response to any given question. To ensure the reliability and validity of the questions, technical statistics were performed, such as frequency, ratio, average, standard deviation, skewness, and kurtosis via SPSS 15.0, item-total correlation and the totality, and reliability analysis. A structural analysis was undertaken via AMOS 7.0 in a bootstrapping method in order to perform a path analysis among variables as well as to assess the suitability of the model. The findings of the study were led to the following conclusions: First, the causal model among green consumer behavior, environmental knowledge and environmental attitudes of students at the university of education is suitable to the empirical analysis on research variables. Second, the environmental attitudes of students at the university of education has a direct, positive effect on green consumer behavior. Third, the environmental knowledge of students at the university of education has an indirect, positive effect on green consumer behavior.

Optimal Design of Flow Measurement System Using Turbine Flowmeter (터빈유량계를 이용한 유량 측정 시스템의 최적 설계)

  • Kim, Hong-Tark;Kim, Boo-Il
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.1
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    • pp.77-84
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    • 2018
  • The turbine flowmeter is selected for high precision and reproducibility at the time of flow rate measurement but causes various uncertainty factors of measurement in the difference between the standard environmental condition at calibration and the environmental condition at the site. Also, a reliable interpolation method is required for use in sections other than calibrated measurement values. Therefore, in this paper, in order to improve the reliability of the flow rate measurement, we designed and manufactured a device that accurately measures the output signal of the turbine flowmeter, interpolates the value of the calibrated result value, and corrects the temperature change in real time We confirmed the reliability of the measurement at the site to carry out the performance verification.

The Effect of Brand Image, Brand Love on Brand Commitment and Positive Word-of-Mouth

  • DAM, Tri Cuong
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.449-457
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    • 2020
  • This study's purpose was to empirically research the effect of brand image and brand love on brand commitment, and positive word of mouth. We analyzed research data from 267 customers at electronics stores in Ho Chi Minh City, Vietnam. The convenient sampling method was used to collect the research sample. The measurement applied a 5-point Likert scale classifying from 1= completely disagree and 5=completely agree. Based on previous studies, the research model was recommended. The Partial Least Squares method was done to examine the measurement model and the structural model. We had estimated the reliability of the scales through Cronbach's alpha and composite reliability. Besides, we had assessed discriminant validity through the Fornell-Larcker standard. The outcome of the study illustrated that brand image had a significantly positive influence on brand love. Besides, the results of the research declared that brand image was positively related to brand commitment. The results also revealed that brand image was positively linked to positive word of mouth. Likewise, the findings of the study disclosed that brand love had a positive impact on brand commitment and positive word of mouth. Additionally, the results of the research confirmed that brand commitment was positively linked to word of mouth.

Development of Message Oriented Middleware for Operational Flight Program in Avionics (항공전자 비행운영프로그램을 위한 메시지 기반 미들웨어 개발)

  • Kim, Jong-Moon;Kim, Ki-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.2
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    • pp.299-305
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    • 2016
  • It is require to design the next generation avionics system while considering applicability under open architecture where standerd communication module is used. In this situation, if the existing schemes cannot guarantee new requirement, new system development is demanded. In this paper, we present design, implementation, and testing procedure for message based middleware to support operational flight program on avionics. System architecture include mission computer (MC) and large area display (LAD) over standard socket communication based on reliable Ethernet. Finally, experimental results demonstrate that the proposed middleware can guarantee real-time with 20msec as well as reliability requirements with no lost packet.

Evaluating the effective spectral seismic amplification factor on a probabilistic basis

  • Makarios, Triantafyllos K.
    • Structural Engineering and Mechanics
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    • v.42 no.1
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    • pp.121-129
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    • 2012
  • All contemporary seismic Codes have adopted smooth design acceleration response spectra, which have derived by statistical analysis of many elastic response spectra of natural accelerograms. The above smooth design spectra are characterized by two main branches, an horizontal branch that is 2.5 times higher than the peak ground acceleration, and a declining parabolic branch. According to Eurocode EN/1998, the period range of the horizontal, flat branch is extended from 0.1 s, for rock soils, up to 0.8 s for softer ones. However, from many natural recorded accelerograms of important earthquakes, the real spectral amplification factor appears to be much higher than 2.5 and this means that the spectrum leads to an unsafe seismic design of the structures. This point is an issue open to question and it is the object of the present study. In the present paper, the spectral amplification factor of the smooth design acceleration spectra is re-calculated on the grounds of a known "reliability index" for a desired probability of exceedance. As a pilot scheme, the seismic area of Greece is chosen, as it is the most seismically hazardous area in Europe. The accelerograms of the 82 most important earthquakes, which have occurred in Greece during the last 38 years, are used. The soil categories are taken into account according to EN/1998. The results that have been concluded from these data are compared with the results obtained from other strong earthquakes reported in the World literature.

Forcing a Closer Fit in the Lower Tails of a Distribution for Better Estimating Extremely Small Percentiles of Strengths

  • Guess, Frank-M.;Leon, Ramon-V.;Chen, Weiwei;Young, Timothy-M.
    • International Journal of Reliability and Applications
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    • v.5 no.4
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    • pp.129-145
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    • 2004
  • We use a novel, forced censoring technique that closer fits the lower tails of strenth distributions to better estimate extremly smaller percentiles for measuring progress in continuous improvement initiatives. These percentiles are of greater interest for companies, government oversight organizations, and consumers concerned with safely and preventing accidents for many products in general, but specifically for medium density fiberboard (MDF). The international industrial standard for MDF for measuring highest quality is internal bond (IB, also called tensile strengh) and its smaller percentiles are crucial, especially the first percentile and lower ones. We induce censoring at a value just above the median to weight lower observations more. Using this approach, we have better fits in the lower tails of the distribution, where these samller percentiles are impacted most. Finally, bootstrap estimates of the small percentiles are used to demonstrate improved intervals by our forced censoring approach and the fitted model. There was evidence from the study to suggest that MDF has potentially different failure modes for early failures. Overall, our approach is parsimonious and is suitable for real time manufacturing settings. The approach works for either strengths distributions or lifetime distributions.

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Reliable Multicast MAC Protocol for Cooperative Autonomous Vehicles (협력적 자율 차량을 위한 신뢰성있는 멀티케스트 MAC 프로토콜)

  • Kim, Jungsook;Kim, Juwan;Choi, Jeongdan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.3
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    • pp.180-187
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    • 2014
  • This paper introduces reliable multicast MAC protocol for cooperative unmanned vehicles. cooperative unmanned vehicles communicate with infrastructure and other unmanned vehicles in order to increase driving safety. They exchange information related to driving and thus it requires real-time and reliable multicast. However, the international vehicular communication standard, IEEE 802.11p WAVE, does not provide a reliable multicast scheme on the MAC layer. To address the problems of reliability, we propose a reliable multicast protocol called WiVCL, which avoids contention and collision. Our evaluation shows that the WiVCL achieves a high degree of reliability and real-time features.