• 한국추진공학회지
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• 제4권1호
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• pp.102-108
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• 2000

세계 여러나라의 유도무기체계에 적용되고 있거나 개발중인 착화기술의 개략적인 특성과 장단점을 제시하고, 각 기술의 수행능력인 성능, 신뢰성, 안전성, 가격 등을 비교 분석하였다. 분석결과, 어느 무기체계에서나 만족될 수 있는 만능적인 착화기술은 없으며 적용요구조건과 비용에 따라 각기 특별한 장단점을 가진다. 그러나 현재 선진국에서 개발되어 시험 적용되고 있는 다이오드 레이져를 이용한 착화방법은 본질적인 잇점들 때문에 차후 유도무기 착화기술에 지배적으로 사용될 것으로 판단된다.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.507-517
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• 2020

The present research intends to examine the relationship between the Big Five personality traits and leadership initiations among the marketing executives in Delhi NCR (INDIA), and seeks to uncover the predictors of leadership initiations within personality traits. The data are collected through online survey method using different social media platforms. A sample of 233 (male =136 and female =97) marketing executive's responses were included. The data collected with the help of self-reported Big Five model inventory and leadership initiation test. The collected data were analyzed statistically by using descriptive statistics, correlation. and stepwise multiple regression analysis. The results revealed that the age of respondents inversely correlated with leadership initiation. Neuroticism revealed significant inverse correlation with leadership initiation, whereas significant positive correlations were found between extraversion, conscientiousness, agreeableness, and leadership initiations, while openness to experience revealed insignificant positive correlation with leadership initiation. Extraversion and conscientiousness appeared as the most dominant personality traits among marketing executives, irrespective of gender, that positively influenced leadership initiation and appeared as the predictor of leadership initiation. In male executives extraversion and age emerged as the predictors of leadership behavior, while in female executives extraversion and openness to experience personality traits appeared as the predictors of leadership initiation.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1588-1596
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• 2022

In the nuclear power plants, stainless steel is widely used for fabrication of various components such as piping and pipe fittings. These piping components are subjected to cyclic loading due to start up and shut down of the nuclear power plants. The application of cyclic loading may lead to initiation of crack at stress raiser locations such as nozzle to piping connection, crown of piping bends etc. of the piping system. Crack initiation can also take place from the flaws which have gone unnoticed during manufacturing. Therefore, prediction of crack initiation life would help in decision making with respect to plant operational life. The primary objective of the present study is to compile various analytical models to predict the crack initiation life of the pipes with notch. Here notch simulates the stress raisers in the piping system. As a part of the study, Coffin-Manson equations have been benchmarked to predict the crack initiation life of pipe with notch. Analytical models proposed by Zheng et al. [1], Singh et al. [2], Yang Dong et al. [25], Masayuki et al. [33] and Liu et al. [3] were compiled to predict the crack initiation life of SA312 Type 304LN stainless steel pipe with notch under fatigue loading. Tensile and low cycle fatigue properties were evaluated for the same lot of SA312 Type 304LN stainless steel as that of pipe test. The predicted crack initiation lives by different models were compared with the experimental results of three pipes under different frequencies and loading conditions. It was observed that the predicted crack initiation life is in very good agreement with experimental results with maximum difference of ±10.0%.

• 터널과지하공간
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• 제14권2호
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• pp.121-132
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• 2004

SB 발파에서 지발뇌관의 기폭초시 오차가 암반파괴 과정에 미치는 영향을 고찰하기 위해 기하조건이 다른 발파모델에 순발뇌관, 전자뇌관 그리고 DS뇌관의 기폭초시 오차를 고려하여 SB 발파에서의 암석파괴과정 해석을 수행하였다. 또한 전자 및 DS지발뇌관을 사용한 SB발파의 발파효과와 영향인자를 고찰하기 위해서 해석결과를 통계적으로 분석하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7547-7554
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• 2015

Background: The use of smokeless tobacco (SLT) among women is increasing in India, especially among those with limited education and resources. Preventing the initiation of SLT among women is critical since it has known negative consequences for oral and reproductive health. Most research on tobacco initiation in India focuses on adolescents. This paper addresses the unrecognized issues of post marital initiation among women of reproductive age, highlighting the importance of reproductive stages in women's tobacco initiation. The objective is to examine the correlates of SLT initiation among low income women in Mumbai from pre-marriage through early marriage, first pregnancy and beyond, using case examples to illustrate initiation during each of these stages. Materials and Methods: In 2011-2012, cross-sectional community level survey data were collected from a representative sample of 409 daily SLT-using married women aged 18-40 years in a low income community in Mumbai. Information on socio-demographics, initiation by reproductive stage, types of tobacco use, childhood exposure to tobacco, learning to use, and initiation influences and reasons were collected through a researcher-administered survey. Univariate and bivariate analysis assessed factors influencing initiation of SLT use by reproductive stage. In addition 42 narratives of tobacco use were collected from a purposive sample of pregnant and non-pregnant married women addressing the same questions in detail. Narratives were transcribed, translated, and coded for key concepts including initiation of tobacco use. Results: Thirty-two percent of women initiated SLT use before marriage, 44% initiated after marriage but before pregnancy, 18.1% initiated during their first pregnancy and the remainder started after their first pregnancy. Mean age of marriage among women in this study was 16 years. Younger women (i.e. age at time of the interview of less than 30 years) were 0.47 [95% CI (0.32, 0.87)] percent less likely to initiate after marriage than women aged more than 30 years. Women who got married before 18 years of age were 2.34 [95% CI (1.40, 3.93)] times more likely to initiate after marriage than their counterparts. Childhood exposure was a predictor for initiating SLT use prior to marriage but not after. Women reporting tooth and gum pain were 1.85 times more likely to initiate after marriage than their counterparts. Husband and neighbours were the most significant influences on post-marital initiation. Narratives highlighted differences in processes of initiation pre and post marriage and during pregnancy. Conclusions: Most tobacco prevention interventions are directed to adolescents in school. This study suggests that especially for low literate or illiterate women, school based interventions are ineffective. To be effective strategies to prevent SLT initiation must reach women in urban areas at or immediately after marriage and during their first pregnancy. Messages must negate culturally rooted beliefs about the health benefits of SLT in order to prevent initiation and onset of daily use.

• Journal of Preventive Medicine and Public Health
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• 제53권6호
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• pp.465-475
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• 2020

Objectives: This study was conducted to examine the association between birth patterns (defined in terms of birth order and interval) with delayed breastfeeding initiation in Indonesia. Methods: A cross-sectional study was carried out using data from the Indonesian Demographic and Health Survey 2017. The weighted number of respondents was 5693 women aged 15-49 years whose youngest living child was less than 2 years old. Multivariable logistic regression was conducted to evaluate associations between birth patterns and delayed breastfeeding initiation after adjusting for other covariates. Results: This study found that 40.2% of newborns in Indonesia did not receive timely breastfeeding initiation. Birth patterns were significantly associated with delayed breastfeeding initiation. Firstborn children had 77% higher odds of experiencing delayed breastfeeding initiation (adjusted odds ratio, 1.77; 95% confidence interval, 1.02 to 3.04; p<0.05) than children with a birth order of 4 or higher and a birth interval ≤ 2 years after adjusting for other variables. Conclusions: Firstborn children had higher odds of experiencing delayed breastfeeding initiation. Steps to provide a robust support system for mothers, especially first-time mothers, such as sufficient access to breastfeeding information, support from family and healthcare providers, and national policy enforcement, will be effective strategies to ensure better practices regarding breastfeeding initiation.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1125-1135
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• 2010

A fundamental characteristic of PMHT (Probabilistic Multi-Hypothesis Tracker) is that the number of targets and initial states of targets in the surveillance area must be a priori known. This requirement is impossible to fulfil in almost every realistic scenario. In the paper, we present two track initiation methods to solve the problem. The proposed track initiation methods are 2-point track initiation and Hough transform track initiation, and they are used to evaluate track initial states and weights for FTD (False Track Discrimination) of the PMHT algorithm. Also suggested as automatic target detection for tracking systems that combines track initiation for target detection with the PMHT algorithm for target tracking in a cluttered environment. A series of Monte-Carlo simulation runs is employed to evaluate the overall system performance with the two track initiation methods and the results are compared and analyzed.

• Journal of Welding and Joining
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• 제21권5호
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• pp.575-581
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• 2003

It has been well known that the ductile cracking of steel would be accelerated by triaxial stress state. Recently, the characteristics of critical crack initiation of steels are quantitatively estimated using the two-parameters, that is, equivalent plastic strain and stress triaxiality, criterion. This study is paid to the fundamental clarification of the effect of geometrical heterogeneity and strength mismatching, which can elevate plastic constraint due to heterogeneous plastic straining, and loading rate on ductile crack initiation behavior. Also, the ductile crack initiation testing were conducted under static and dynamic loading using round bar specimens with circumferential notch and strength mis-matching. The result showed that the nominal strain at ductile crack initiation of circumferential notch specimens small then the round bar specimens for effect of geometrical discontinuity. Also, the nominal strain at ductile crack initiation was decreased with decrease of notch root radius of curvature.

• Structural Engineering and Mechanics
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• 제56권2호
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• pp.257-273
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• 2015

Numerical value of correlation between effective parameters in the strength of a structure is as important as its stochastic properties in determining the safety of the structure. In this article investigation is made about the variation of coefficient of correlation between effective parameters in corrosion initiation time of reinforcement and the time of concrete cover cracking in reinforced concrete (RC) structures. Presence of many parameters and also error in measurement of these parameters results in uncertainty in determination of corrosion initiation and the time to crack initiation. In this paper, assuming diffusion process as chloride ingress mechanism in RC structures and considering random properties of effective parameters in this model, correlation between input parameters and predicted time to corrosion is calculated using the Monte Carlo (MC) random sampling. Results show the linear correlation between corrosion initiation time and effective input parameters increases with increasing uncertainty in the input parameters. Diffusion coefficient, concrete cover, surface chloride concentration and threshold chloride concentration have the highest correlation coefficient respectively. Also the uncertainty in the concrete cover has the greatest impact on the coefficient of correlation of corrosion initiation time and the time of crack initiation due to the corrosion phenomenon.

• 대한기계학회논문집A
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• 제27권7호
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• pp.1185-1192
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• 2003

Governing parameters for determination of the location of crack initiation and direction of crack initiation were investigated by performing fretting fatigue tests and analysis on Al 2024-T351. Fatigue tests were carried out using biaxial fatigue machine. It was shown that the dominant fatigue crack tended to initiate at the outer edge of one of the four bridge pads, growing at an angle beneath a pad, before turning perpendicular to the orientation of the axial load. Distribution of stresses generated during fretting fatigue loading along the interface was calculated by elastic FE simulation. It can be known that the location of crack initiation can be predicted by using the maximum tangential stress range. Futhermore, the crack initiation direction can also be predicted by a maximum tangential stress range.