• Title/Summary/Keyword: reliability factors

Search Result 4,311, Processing Time 0.035 seconds

Numerical Study on Variation of Penetration Performance into Concrete by Penetrator Nose Shape (침투자의 노즈 형상에 따른 콘크리트 침투성능 변화에 관한 수치적 연구)

  • Ju, Yongwon
    • Journal of the Korea Society for Simulation
    • /
    • v.27 no.3
    • /
    • pp.109-116
    • /
    • 2018
  • In order to destroy the hard target, it is essential to develop a penetration warhead with high penetration performance. To design a penetration warhead, this paper discusses the effect of nose shape factors such that nose shape, nose length, nose tip diameter, on the penetration performance of the penetrator. AUTODYN-2D has been used to conduct the computational analysis. The experimental result of Forrestal, and a simulation result have been compared to verify the reliability of computational analysis. Computational results show that the nose length have more influence on the penetration performance than the nose shape. Furthermore, simulation results show that the penetration performance can be improved by increasing the nose tip diameter to a specific value, when the nose length of the penetrator is uniform.

A Study on the Customer's Selection Attributes for Japanese Chain Restaurants in Seoul.Kyunggi Area (서울.경기지역 일식체인 레스토랑의 선택속성에 관한 연구)

  • Yun, Tae-Hwan;Lee, Soo-Bum;Yoon, Hye-Hyun
    • Journal of the Korean Society of Food Culture
    • /
    • v.19 no.1
    • /
    • pp.1-11
    • /
    • 2004
  • The specific purposes of this study are that ; 1) to investigate the distinguished selection attributes on performance of Japanese chain restaurant according to general characteristics of the respondent ; 2) to find out relationships between selection attributes on performance for Japanese restaurant and customer's satisfaction Frequency analysis. one-way ANOVA, reliability analysis, factor analysis, multiple regression were used to analyze the data. Total 350 questionnaires were distributed and 312 were replied(89.14%). Selection attributes on performance for Japanese chain restaurant was divided into 7 factors. There are Factor1 'Store Image & Kindness', Factor2 'Sanitation & Taste', Factor3 'Approximation & Children's Menu', Factor4 'Delivery & Business Hours', Factor5 'Food Quantity & Korean Food', Factor6 'Service & Parking' Factor7 'Price & Publicity'. Monthly income, eating-out expense per once and type of companion have significant influences on selection attributes for performance. Customer's total satisfaction is significantly affected by selection attributes on performance. Factor7 'Price & Publicity' has the most significant influence on customer's satisfaction. We expect that the results can be used to provide basic information to plan marketing strategies, and take improved customer's satisfaction for Japanese chain restaurants.

Assessment Indexes for Activation of Urban Public Space (도시의 공공공간 활성화를 위한 평가 지표 연구)

  • Kim, Do-Gyoung;Moon, Jeong-Min
    • Journal of the Korean housing association
    • /
    • v.24 no.3
    • /
    • pp.109-119
    • /
    • 2013
  • Today's urban spaces require diverse functions according to segmented social changes. Urban public space needs to be a field of mutual exchange, respect of diversity, and communication. According to these needs, an identity which reaches the public should be developed and realized. Therefore, this study is to present indexes for evaluating public space as a means to improve urban identity along with developing an awareness of possible problems. For this purpose, this study found out and analysed factors of evaluation indexes for the most fundamental public spaces which form cities in order to develop directions for deciding on indexes for public space and activation of that public space. An empirical analysis was conducted with the use of a questionnaire with evaluation indexes, reliability, and validity of properties of the space to be analysed and the evaluation items were tested. Based on the results, the study compared and analysed the differences between groups with independent variables (evaluation indexes) and general characteristics through a t-test. As a result, it was discovered that easy and safe accessibility in the use of urban parks as public space was statistically significant. Such results show that accessibility is the most significant factor in the use of parks.

Consumer's Wel-being: The Conceptualization and the Development of Consumption Life Level Scale (소비자의 복지 - 소비생활수준의 개념 및 척도개발을 중심으로 -)

  • Chang, Hyun-Sun
    • Journal of Families and Better Life
    • /
    • v.28 no.6
    • /
    • pp.207-220
    • /
    • 2010
  • This study is intended to create a tool which can identify the concept of consumption life level and to develop a standardized scale to measure consumption life level. Based on it, the concept and perspective of consumption life level was formed and then the scale for measuring it was developed. To develop the scale, the scale was firstly formed by extracting questions through a literature survey, and verifying validity through experts' opinions. Then the final scale was developed by conducting a questionnaire survey for consumers. A preliminary 27-item scale was developed through a literature review. 1000 consumers responded to an online survey using the preliminary scale. This research was made with the intention of not only supplying academic data on the consumer's consumption life level but also understanding the consumer's basic behavior patterns. Then a series of tests: test-retest, item-to-total correlation, and Cronbach's reliability coefficient and factor analysis were conducted using the survey data and the final 20-item scale was constructed in the end. The consumer's consumption life level scale consisted of 4 factors.

Framework of Owner-driven Lean Construction for Plant Construction (발주자 주도형 린 건설에 대한 기초 연구;플랜트 건설공사를 중심으로)

  • Ryu, Chung-Kyu;Han, Seung-Heon;Park, Jung-Jun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
    • /
    • 2007.11a
    • /
    • pp.647-651
    • /
    • 2007
  • The Lean Construction is adopted from Lean Principle of Manufacturing Industry in the early of 1990, that has been providing theoretical background and good practical implementation for maximizing customers' satisfaction and improving productivity through minimizing the waste factors in the construction operations. The Last Planner System(LPS), one of the elementary techniques of Lean Construction, aims for improving the work reliability and reducing variability by measuring and managing the daily or weekly performance for overcoming the weakness of recent complex schedule management tools such as Critical Path Method. This research is propose a framework for implementation of LPS conducted by owner in plant construction.

  • PDF

Performance Analysis and Evaluation of 3kW Grid-Connected PV Systems (3kW급 계통연계형 태양광발전시스템의 성능특성 평가분석)

  • So, Jung-Hun;Jung, Young-Seok;Yu, Gwon-Jong;Choi, Ju-Yeop;Choy, Ick
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.53 no.8
    • /
    • pp.509-516
    • /
    • 2004
  • The concerns of distributed generations including photovoltaic(PV) system have been increased around the world since PV system is becoming widespread as a clean and gentle energy source for earth. In the future high density grid-connected PV systems will be interconnected with distribution network. As a result, the stability and long-term reliability of PV systems have become more important issues in this area. Grid-connected PV systems have been installed and monitored at field demonstration test center(FDTC) and also data acquisition system(DAS) has been constructed for measuring and analyzing performance of PV system to observe the overall effect of environmental conditions on their operation characteristics. The performance of PV system has been evaluated and analyzed for component perspective (PV array and power conditioning system) and global perspective (system efficiency, capacity factor, and electrical power energy) by field test and loss factors of PV system.

The Design, Fabrication, and Characteristic Experiment for Control Rod Position Indicator Using Reed Switch in System-Integrated Modular Advanced Reactor (리드스위치를 이용한 일체형원자로용 제어봉 위치지시기 설계 제작 및 특성해석)

  • Hur, Hyung;Kim, Jong-In;Kim, Kern-Jung
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.52 no.8
    • /
    • pp.452-461
    • /
    • 2003
  • The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indicator system and its actual implementation in the existing nuclear power plants in Korea was performed first. The control rod position indicator having the high performance for SMART was developed on the basis of RSPT technology identified through the survey. The arrangement of permanent magnet and reed switches is the most important procedure in the design of control rod position indicator. The hysteresis of reed switches is one of the important factors in a repeat accuracy of control rod position indicator as well. This paper investigates efficiency of the magnetic flux concentrator and the hysteresis using FEM and verified differences in physicals characteristics by comparing the results of FEM and those of the experiment. As a result, it is shown that the characteristics of prototype control rod position indicator have a good agreement with the results of FEM.

Comparison of 29 Diagrams of Lung Originated from Ming Tang Zang Fu Tu (明堂臟腑圖) (명당장부도(明堂臟腑圖)에서 기원한 폐장도(肺臟圖) 29종의 비교)

  • Jo, Hak-Jun
    • The Journal of Korean Medical History
    • /
    • v.29 no.1
    • /
    • pp.11-31
    • /
    • 2016
  • Objectives : The goal of this paper is to research what affected diagrams of lung originated from Ming Tang Zang Fu Tu during the time they were changed in. Methods : Diagrams of lung in Traditional Chinese and Japanese medical books had been collected as many as possible. Besides being grouped by Huang Longxiang (黃龍祥)'s classification, they were analysed by 4 form factors, e.g. shape, number, veins and petiole of leafs. Results : Reliability of this methods had been checked on by the correspondence with Huang's 14 standard books, before 29 diagrams of lung were selected from 33 books including 13 books that Huang had already made his proposal. The lobes in most of diagrams resembled 6 lanceolate or long oval leafs, or a maple leaf with 5 indentations. In most of diagrams, veins of leafs were described variously, more or less than 9 nodes often drew in petioles. Conclusions : Suwen (素問), Nan Jing (難經) and Wang Bing would had steadily worked on 29 diagrams of lung, since diagram of lung stemmed from Ming Tang Zang Fu Tu, went out into the world in Zhen Jiu Ju Ying (鍼灸聚英). But they were not drawn through dissection during same periods.

Scheme and application of phase delay spectrum towards spatial stochastic wind fields

  • Yan, Qi;Peng, Yongbo;Li, Jie
    • Wind and Structures
    • /
    • v.16 no.5
    • /
    • pp.433-455
    • /
    • 2013
  • A phase delay spectrum model towards the representation of spatial coherence of stochastic wind fields is proposed. Different from the classical coherence functions used in the spectral representation methods, the model is derived from the comprehensive description of coherence of fluctuating wind speeds and from the thorough analysis of physical accounts of random factors affecting phase delay, building up a consistent mapping between the simulated fluctuating wind speeds and the basic random variables. It thus includes complete probabilistic information of spatial stochastic wind fields. This treatment prompts a ready and succinct scheme for the simulation of fluctuating wind speeds, and provides a new perspective to the accurate assessment of dynamic reliability of wind-induced structures. Numerical investigations and comparative studies indicate that the developed model is of rationality and of applicability which matches well with the measured data at spatial points of wind fields, whereby the phase spectra at defined datum mark and objective point are feasibly obtained using the numerical scheme associated with the starting-time of phase evolution. In conjunction with the stochastic Fourier amplitude spectrum that we developed previously, the time history of fluctuating wind speeds at any spatial points of wind fields can be readily simulated.

Evaluation of Car Seat Using Reliable and Valid Vehicle Seat Discomfort Survey

  • Deros, Baba Md.;Daruis, Dian Darina Indah;Nor, Mohd Jailani Mohd
    • Industrial Engineering and Management Systems
    • /
    • v.8 no.2
    • /
    • pp.121-130
    • /
    • 2009
  • Subjective evaluation has always been regarded as a branch of social science research. Hence, in scientific and especially engineering points of view, its development is always taken for granted despite the importance of its effects on the design and development decisions. In the past, at least two automotive seat survey questionnaires have been developed with high statistical validity and reliability. Nonetheless, both were not local while subjective perception very much depends on demographic background factors. It is felt that since vehicle seat comfort is an important aspect in a seat design, a local sense should be put into the survey that is used as the subjective tool. The proposed vehicle seat discomfort survey questionnaire was developed in dual languages; English and Malay. Malay language is the national language of Malaysia, where the survey was tested. Beside inputs from literatures, key informant interviews helped in establishing the appropriate terms used as survey items. Three experimental runs on two different seats by 22 paid subjects showed that the developed questionnaire is reliable and valid. Furthermore, criterion validity analysis on the survey and previously developed survey showed significant correlation at 0.01 significance level.