• 한국세라믹학회지
• /
• 제53권2호
• /
• pp.139-144
• /
• 2016

The dependence of the microwave dielectric properties of the glass-ceramic composite $0.9CaMgSi_2O_6-0.1MgSiO_3$ on the crystallization behaviour was investigated as functions of the $TiO_2$ content and heat-treatment temperature. The crystallization behaviour of the specimens was evaluated via a combination of the Rietveld and reference-intensity ratio methods. For specimens with a $TiO_2$ content of up to 1 wt.%, a monoclinic diopside phase was formed, whereas a secondary $TiO_2$ phase was formed with further increases in the $TiO_2$ content. The quality factor (Qf) of the specimens was strongly dependent on the degree of crystallization. The highest Qf value was obtained with a $TiO_2$ content of 0.5 wt.%, which was improved by increasing the heat-treatment temperature. The dielectric constant (K) was affected by the size of the crystallites and the $TiO_2$ content. The temperature coefficient of the resonant frequency (TCF) was nearly constant for all of the specimens, regardless of the $TiO_2$ content or heattreatment temperature.

• Computers and Concrete
• /
• 제2권2호
• /
• pp.97-110
• /
• 2005

Rheological behaviour of fresh concrete is an important factor in controlling concrete quality. It is recognized that the measurement of the slump is not a sufficient test method to adequately characterize the rheology of fresh concrete. To further understand the slump measurement and its relationship to the rheological properties, an elasto-viscoplastic, 2-D axisymmetric finite element (FE) model is developed. The FE model employs the Bingham material model to simulate the flow of a slump test. An experimental program is carried out using the Slump Rate Machine (SLRM_II) to evaluate the finite element simulation results. The simulated slump-versus-time curves are found to be in good agreement with the measured data. A sensitivity study is performed to evaluate the effects of yield stress, plastic viscosity and cone withdrawal rate on the measured flow curve using the FE model. The results demonstrate that the computed yield stress compares well with reported experimental data. The flow behaviour is shown to be influenced by the yield stress, plastic viscosity and the cone withdrawal rate. Further, it is found that the value of the apparent plastic viscosity is different from the true viscosity, with the difference depending on the cone withdrawal rate. It is also confirmed that the value of the final slump is most influenced by the yield stress.

• 아태비즈니스연구
• /
• 제4권2호
• /
• pp.31-40
• /
• 2013

This paper portrays the perception of buying behaviour, factors of product preferences and product switch-over among women consumers in Vellore district of Tamil Nadu. To conduct this study, 300 respondents from 20 village blocks of Vellore district were selected using stratified random sampling as the technique and descriptive sampling as the design. The study came out with interesting results and conclusions. It was found that more than half of the respondents were purchasing the product without a bill. It was also found that the respondents who repaired their product in the authorized service centre during warranty period did not continue the same after the warranty period and preferred nearby repair shops. It was further found that more than half of the respondents were checking expiry date and quality standards while purchasing a product. The study's scope was limited to women consumers at Vellore district. It could be used for further research in other aspects such as gender comparison in Vellore district and comparison with other districts of Tamil Nadu and other states of India. It was suggested that there is still a necessity to upgrade the standard of the people in many aspects like education, occupation and level of income, which shall help them to compete with the neighboring cities on living standards.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2006년도 추계학술대회 논문집
• /
• pp.1354-1363
• /
• 2006

Until now, NATM(New Austrian Tunneling Method) has been increasingly developed based on concept of making use of ground as support. Also, NATM in its essence is a method of risk based on monitoring behaviour of tunnel. This Monitoring is irreplaceable for the quality construction of tunnel, and safety of tunnel itself. Pre-reinforcement ahead of a tunnel face using long steel pipes in NATM, known as the RPUM(Reinforced Protective Umbrella Method), is the auxiliary method to sustain the stability of a tunnel face and reduce the ground settlements. Since design of RPUM has been dependent on the empirical design, it is necessary to develop the improved design methods. In this study, to understand behaviour of steel pipes, it is monitored displacement of tunnel crown, axial force of rock bolt, displacement and axial stress of steel pipes. Also, in order to clarify the mechanical behaviour and RPUM effects, 3-Dimensional numerical analysis is performed that various cases of different parameter combinations including original length and repeated length of steel pipes, installation width and angle, repeated length of steel. In the results of comparison monitoring with analysis, it is suggested more economical and efficient design technique than empirical design methods.

• International Journal of Computer Science & Network Security
• /
• 제22권5호
• /
• pp.182-192
• /
• 2022

All the aspects of human life have been affected by the novel coronavirus (Covid-19). It has rapidly spread in most countries including the Kingdom of Saudi Arabia. As a result, early precautionary actions aiming to minimise the virus effect are taken by the Saudi government. One of these actions is the sudden shift to online classes and suspending the attendees to all educational institutes. Such immediate change can have a significant effect on the educational process, especially for students. One can argue that students' information-seeking behaviour within the current situation can affect their learning quality and outcomes. Therefore, this paper examines the Saudi students' information-seeking behaviour by taking a sample of students from Umm Al-Qura University. A descriptive analysis is conducted with 193 students and two approaches are used to collect data, questionnaire and semi-structured interview. The results showed that the majority of students face difficulties when searching and retrieving e-resources from the university library website. The problems range from mainly poor User Experience (UX), network connection, multiple errors and lack of subscription with academic publishers.

• 한국학교ㆍ지역보건교육학회지
• /
• 제9권1호
• /
• pp.47-61
• /
• 2008

Objectives: This study examined to explain the practical health behaviour and health-related quality of life, and their influencing factors in high school students. Methods: Total of 718 high school students from 1 school in Seoul were assessed with a self-administered questionnaire regarding general characteristics, health related characteristics, obesity index(Height and weight calculated by using the relative weight law: obesity group>20%, overweight group $10{\sim}20%$, normal weight group $-10{\sim}10%$, under weight group <-10%), health behaviour in school-aged children(eating, exercise and weight control) and health-related quality of life(PedsQLTM4.0 Generic Core Scale: physical health, emotional functioning, social functioning, school functioning). Results: Major results were as follows. 1. The rate of obesity by obesity index was 5.3% of high school students. Obesity incidence in adolescents was mainly associated with gender and parents whether obesity. 2. Perceived health status was lower in obese adolescents than in normal adolescents. 3. The rate of miss a breakfast was 37.9%, and obesity group than normal weight group were fruits, vegetables and milk intake at least, a lot of fastfood intake. During the past week, followed by intense physical activity, and overweight consumed a lot of time for TV and the Internet. Overall, under weight group and normal weight group belong to the students evaluated fatter than themselves. Weight control for weight loss, gain and maintain was grater in obesity group than in normal weight group. Weight loss showed highest scores in overweight group which appeared significant difference. 4. Obese adolescents compared with other groups, reported lower total QOL score and all QOL in domain, and especially social functioning showed significant differences. 5. Factors influencing the adolescents's QOL were found to be gender, perceived health status and exercise. Conclusions: High school girls were aware of their bad health status and likely to improve the QOL by practicing health behaviour. But obese adolescents were likely to degrade the quality of life by reducing the practice of health behaviors. So further school-based education about proper practical health behaviors and obesity prevention is necessary.

• International Journal of Quality Innovation
• /
• 제6권3호
• /
• pp.1-18
• /
• 2005

This paper presents the empirical research results conducted in a Swedish care organization for elderly and handicapped. The objective of the research was to empirically assess the implementation and practices of a quality system (ISO 9000) from an organizational change and development perspective. The empirical data were collected through multiple methods; interviews were carried out with key-persons and leadership in the organisation and surveys were conducted to all employees. Interactive methods have been applied to various groups in the organisations e.g., directors, supervisors, and the leadership of the quality project and the local politicians. The empirical findings indicate, among others, that the implementation processes were received and perceived differently in the different parts of the care organisation due to different leadership strategies and employee involvement policies. Other critical factors such as acceptance, resistance, motivation, commitment, the role of leadership, learning possibility, etc. have also been investigated, analysed and discussed. Finally some recommendations on how to approach organisational change as well as strategies for implementing a quality system in the care sector are presented.

• 자원ㆍ환경경제연구
• /
• 제18권2호
• /
• pp.191-215
• /
• 2009

시장에는 다양한 속성과 가격의 제품이 동시에 존재하고 있으며, 소비자가 이 제품들 중에서 어떠한 제품을 선택했는지 살펴봄으로써 그 소비 행위가 어느 정도 효율적이었는지 판단할 수 있다. 본 연구에서는 소비 효율성을 가격과 속성의 관점에서 정의하고, DEA 기법을 이용하여 한국의 주요 정보통신 및 전력 제품에 대한 소비자 효율성을 측정하고자 하였다. 분석 결과 에어컨, TV, 디지털 카메라, MP3 플레이어, 컴퓨터 시장에서는 상대적 효율성이 낮은 제품이 많이 선택된 반면, 냉장고와 세탁기 시장에서는 소비자의 효율성 분포가 정규 분포에 가까운 형태로 나타났다. 또한 정보 구득 관련 항목에 대한 설문 결과를 함께 고려하여 제품별 효율성 차이를 설명하고자 하였으며, 마지막으로 개별 소비자의 효율성과 특성 변수가 전력 사용량에 미치는 영향을 분석하였다. 본 연구는 소비 효율성이라는 개념을 정량적으로 측정하여 해당 제품의 시장에 대한 유용한 정보를 제공할 수 있으며, 제품의 구매와 에너지 사용을 함께 고려함으로써 분석의 범위를 확대하였다는 점에서 의의가 있다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2001년도 가을 학술발표회 논문집
• /
• pp.133-145
• /
• 2001

This paper presents quality and measure controls of Plastic Board Drains(PBD) for improvement of soft ground. Laboratory and field tests has been carried out to evaluate the quality of PBD focussing on : discharge capacity of flow area; permeability of filter sleeve; migration of fine particles; deformed shape of PBD; consolidation of clay in the close vicinity of PBD; tensile strength of PBD; long-term consolidation behavior of clay-PBD. Test results show that the quality of PBD is sufficient to perform the improvement of soft silty and clayey ground. But, geotechnical engineer must make efforts minimizings of PBD damage and ground disturbance, continuity of drainage system during construction. Adequate monitoring system should apply at ground focussing on number, location, and accuracy of geotechnical instrumentation, measurement and evaluation of data for ground behaviour.

• 동력기계공학회지
• /
• 제4권1호
• /
• pp.51-59
• /
• 2000

Active suspension systems have been using for improving ride quality and stability for vehicles. An active suspension system is composed of a hydraulic pump, pressure control valves, hydraulic dampers, vehicle body, tires and other components. In this study, the mathematical model for the active suspension system based on the quarter car concept is derived, and a program for analysing the dynamic behaviour of the suspension system is developed. The computed results by the developed program are compared with the experimental results for confirming the reliability and usefulness of the developed program.