• 대한기계학회논문집A
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• 제21권3호
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• pp.519-527
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• 1997

AISI 316 steel has been used extensively for heater and boiler tube of the structural plants such as power, chemical and petroleum plants under severe operating conditions. Usually, material degradation due to microcrack or precipitation of carbides and segregation of impurity elements, is occured by damage accumulated for long-term service at high temperature in this material. In this study, the effect of aging time on fracture toughness was investigated to evaluate the measurement of material degradation. The elastic-plastic fracture toughness behaviour of AISI 316 steel pipe aged at $550^{\circ}C$for 1h-10000h (the aged material) was characterized using the single specimen J-R curve technique and eletric potential drop method at normal loading rate(load-line displacement speed of 0.2mm/min) in room temperature and air environment. The fracture toughness data from above experiments is compared with the $J_{in}$ obtained from predicted values of crack initiation point using potential drop method.

• International Journal of Human Ecology
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• 제5권2호
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• pp.111-122
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• 2004

This paper outlines the findings of a consumer survey conducted in 1996 and 2001 by the University of Bonn, Germany, across 15 European countries. The survey involved a sample of 3,300 respondents in 1996 and around 11,000 respondents in 2001, throughout all 15 EU countries. Children and adolescents, between the ages of 10 and 17, were surveyed about their consumption habits and their attitudes towards the environment. The paper outlines the key findings on 'Children's fears and future prospects'. Children are exposed to a great mass of information, not only derived from the media but also from what they experience directly in their everyday-life. Some of this information translates into worries that adopt a clearer (more realistic) form when children become adolescents, as they might be easily involved in those events, and the understanding of the processes that may cause or continue them is deeper. Today's children and adolescents are under more pressure, since the social/political/economical spectrum is constantly changing. Change produces anxiety, fear of what will result from these transformations, as it implies that the social order will be reorganized. This paper reports on a long term comparative study among children and adolescents throughout the European Union, analyzed by country, age group and gender. It draws different preoccupations of young generations and consequent future expectations. It concludes by considering the influence of social and political organizations, as well as the family, on children and adolescents, as these might help to sustain a positive attitude towards various future events.

• 한국공간구조학회논문집
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• 제16권1호
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• pp.35-42
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• 2016

Until recently, almost all ETFE film structures that have been erected is the cushion type because there are problems at lower allowable strength under elastic range and viscosity behaviour such as creep and relaxation of ETFE films under long-term stresses. But the number of tension type structures is currently increasing. This paper proposes the stretch fabrication of ETFE film to verify the applicability of ETFE films to tensile membrane structures. First of all, to investigate the possibility of application on tensile membrane structures, the stretch fabrication test is carried out, and it is verified that it is possible to increase the yield strength of the film membrane structures. After simulating the experiment also carries out an analytical investigation, and the effectiveness of the elasto-plastic analysis considering the viscous behavior of the film is investigated. Finally, post-aging tension measurement is conducted at the experimental facilities, and the viscosity behavior resulting from relaxation is investigated with respect to tensile membrane structures.

• 방사성폐기물학회지
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• 제18권3호
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• pp.407-414
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• 2020

Thermal decomposition of the uranyl phosphate mineral phase meta-ankoleite (KUO₂PO₄·3H₂O) has been considered in relation to high temperature thermal sintering for the immobilisation of a uranyl phosphate containing waste. Meta-ankoleite thermal decomposition was studied across the temperature range 25 - 1200℃ under an inert N₂ atmosphere at 1 atm. It is shown that the meta-ankoleite mineral phase undergoes a double de-hydration event at 56.90 and 125.85℃. Subsequently, synthetically produced pure meta-ankoleite remains stable until at least 1150℃ exhibiting no apparent phase changes. In contrast, when present in a mixed waste the meta-ankoleite phase is not identifiable after thermal treatment indicating incorporation within the bulk waste either as an amorphous phase and/or as uranium oxide. Visual inspection of the waste post thermal treatment showed evidence of self-sintering owing to the presence of glass former materials, namely, silica (SiO₂) and antimony(V) oxide (Sb₂O₅). Therefore, incorporation of the uranium phase into the waste as part of waste sentencing and immobilisation via high temperature sintering for the purpose of long-term disposal is deemed feasible.

• Journal of Dairy Science and Biotechnology
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• 제17권1호
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• pp.39-49
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• 1999

Since IMF relief financing, domestic economy has been rapidly cooled down. At this point that we predict an overall decrease of production and sale of industries, cooperative marketing activities of the whole dairy industry are required to promote milk consumption. As everyone knows, advertisement is only one of the various factors that affect sales. Other factors include price, distribution, package, promotion, and consumer's needs and taste. The objectives of the cooperative advertising campaign should be trial purchase of new consumers, maintenance of brand loyalty of existing consumers, more positive experience of using the product, and increase of frequency of purchase. Long term analysis is essential to making these kinds of behaviour changes. Also the objectives of the communication program should be a shift of awareness of milk from 'a basic health food for children' to a substitute to the beverage even for adults. To share database of consumers among companies, we need to find ways to use interactive on-line services, the internet, D.M. events and so on as well as the mass media. It should be a precondition that the main body of the cooperative advertisement includes the milk processing board, dairy companies, livestock cooperations, farmers and the Government. To assure continuous, activities to promote milk consumption, the Government should take the lead in legislating 'An enforcement ordinance for milk promotion and research', and seek complementary measures and support to establish the ordinance.

• Wind and Structures
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• 제1권2호
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• pp.183-199
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• 1998

This paper discusses some of the findings arising from long-term monitoring of the wind effects on a transmission tower located on an exposed site in South-West England. Site wind speeds have been measured, together with the foundation loads at the base of each of the four legs. The results show good correlation between the wind speeds and leg strains (loads) for a given wind direction, as expected, for wind speeds in excess of 10 m/s. Comparisons between the measured strains and those determined from the UK Code of Practice for lattice towers (BS8100), for the same wind speed and direction, show that the Code over-estimates most of the measured foundation loads by a moderate amount of about 14% at the higher wind speeds. This tends to confirm the validity of the Code for assessing design foundation loads. A finite element analysis model has been used to examine the dynamic behaviour of the tower and conductor system. This shows that, in the absence of the conductor, the tower alone has similar natural frequencies of approximately 2.2 Hz in the both the first (transversal) and second (longitudinal) modes, whilst for the complete system and conductor oscillations dominate, giving similar frequencies of approximately 0.1 Hz for both the first and second modes.

• Asia pacific journal of information systems
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• 제34권1호
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• pp.351-371
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• 2024

This study aims to assess the impact of chatbot usability and demographics on continuous intention to use across different sectors. The research employed Braun's Bot Usability Scale (BUS11) to measure chatbot usability, focusing on accessibility, quality, conversation quality, privacy risk, and response time. A total of 187 participants completed a survey as part of this study. Variance-based SEM was utilized to examine relationships and test hypotheses. This study contributes to the ongoing discourse on chatbot adoption and user behaviour. It enhances the understanding of chatbot usability, highlighting the role of age in continued intention to use chatbots. The findings suggest that different age groups may possess specific preferences and expectations regarding chatbot usability. These differing preferences can influence their intention to continue using this technology. The study reveals that chatbot usability significantly impacts continuous intention to use and that age moderates the relationship between perceived conversation quality, information, privacy, security, and continuous intention to use. Based on the study's results, it is recommended that chatbot designers enhance usability to promote long-term adoption and usage.

• 대한치과보철학회지
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• 제43권6호
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• pp.717-726
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• 2005

Statement of problem. One of the common problems of provisional crown and fixed partial denture materials is that when they are subjected to constant loads for a long period of time, they exhibit a dimensional change (creep). Purpose. The aim of this study was to investigate the viscoelastic behaviour of polymer-based provisional crown and fixed partial denture materials with time at constant compressive load. Material and methods. Three dimethacrylate-based materials (Protemp 3 Garant, Temphase, Luxatemp) and one monomethacrylate-based material (Trim) were selected. Dimensional changes of the specimens were recorded by a LVDT to evaluate their viscoelastic behavior and creep strain. For all specimens, two loading procedures were used. At first, static compressive stress of 4 MPa was applied for 30 minutes and followed by 1 hour of strain recovery. Then, after 24 hours of water storage, the specimens were loaded again. The creep values between materials were statistically analyzed using one-way ANOVA and multiple comparison $Scheff\acute{e}$ test. Independent samples t-test was also used to identify the difference of creep strain between first and secondary loading conditions at the significance level of 0.05. Results. Following application of the first loading, Trim showed the highest maximum creep strain (32.7%) followed by Luxatemp, Protemp 3 Garant and Temphase, with values of 3.78%, 2.86% and 1.77%, respectively. Trim was significantly different from other materials (P<0.05), while there were no significant differences among Luxatemp, Protemp 3 Garant and Temphase (P>0.05). The highest recovery and permanent set of Trim, were significantly different from those of others (P<0.05). At the secondary loading of the dimethacrylate-based materials, creep deformation, recovery and permanent set decreased and the percentage of recovery increased, while in Trim, all values of the measurements increased. This result showed that the secondary loading at 24 hours produced a significant creep magnitude. Conclusion. The dimethacrylate-based provisional crown and fixed partial denture materials showed significantly higher creep resistance and lower deformation than the monomethacrylate-based material. Thus, monomethacrylate-based materials should not be used in long-term stress-bearing situations.

• 한국유통학회지:유통연구
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• 제16권1호
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• pp.65-93
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• 2011

본 연구에서는 관리형 유통경로의 구조적 요인들인 공급자 특유투자, 커뮤니케이션, 소매상 의존도가 신뢰에 미치는 효과를 검토하고자 하였다. 또한 이러한 변수들에 대한 관계수명주기의 조절효과를 밝히고자 하였다. 관계적 거래는 하루아침에 성사되는 것이 아니라 장기간에 걸친 반복적 거래 및 사회적 맥락(social context)이 누적된 결과로 발생하기 때문에 관계마케팅을 성공적으로 수행하기 위해서는 관계수명주기에 대한 단계별 검토가 우선되어야 한다. 작물보호제 소매상 296명으로부터 설문자료를 수집하여 분석한 결과, 공급자에 대한 소매상의 의존도가 신뢰를 가장 크게 증가시키는 것으로 나타났다. 특히 관계가 발전할수록 의존도의 영향력은 점점 더 커졌다. 따라서 공급자는 차별화된 제품과 서비스를 제공하여 시간의 흐름에 따라 소매상의 의존도가 더욱 높아질 수 있도록 노력해야 한다. 그리고 공급자 특유투자는 관계 초반에 신뢰를 증가시키는 역할을 하는 것으로 나타났다. 반면에 성숙기 이후에는 유의한 영향력을 보여주지 않았다. 이는 관계 초기에는 상대방을 평가하는 단서가 특유투자에 불과하기 때문에 특유투자의 효과가 크게 나타나지만 관계가 발전하면 상대방을 평가할 수 있는 여러 가지의 단서를 획득하게 되어 특유투자의 효과가 적은 것으로 볼 수 있다. 또한 양자간의 커뮤니케이션은 신뢰를 높여주는 것으로 나타났으며 신뢰는 장기지향성에 긍정적인 영향을 미치는 것으로 나타났다. 성숙기보다 강화기에서 커뮤니케이션의 영향력은 더 크게 나타났다. 본 연구는 관리형 시스템의 관계변수인 공급자 특유투자, 소매상 의존도, 양자 간 커뮤니케이션을 통합적으로 검토하였다는 점에서 의의를 찾을 수 있다. 그리고 관계수명주기의 조절효과를 검토함으로써 관계의 발전단계에 따른 차별적 전략을 제안할 수 있었다.

• 시큐리티연구
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• 제55호
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• pp.169-192
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• 2018

이 연구에서는 잉글랜드와 웨일즈의 '2011년 경찰 개혁 및 사회적 책임에 관한 법'과 관련된 최근 경찰 개혁 전략을 평가하였다. 경찰 개혁 전략 중 가장 중요한 변화는 지역치안위원장에게 경찰인력 운용뿐만 아니라 관할 지역의 범죄를 줄이는 책임도 부여하였다는 것이다. 이로 인해 지역치안위원장은 지방 정부 및 지역 안전 파트너십과도 긴밀히 협력해야 하며, 그 전신인 지방경찰위원회보다 보다 많은 임무와 큰 권한을 갖게 되었다. 이 연구는 또한 지역 경찰 지휘관을 대상으로 한 설문 조사를 통해 범죄의 성향과 정도를 평가하고자 하였다. 이 설문 조사는 강력 범죄보다는 사소한 범죄 및 반사회 범죄로 인한 치안수요가 급증한 것을 보여주었다. 지역치안위원장 제도의 도입은 경찰의 우선순위가 대중의 우선순위와 점차 일치하고 있으며, 반사회적 행동이 이제는 일반적 범죄보다 주민들의 삶에 더 큰 영향을 미치고 있다는 것을 의미한다. 그리고 이 연구는 윈저리뷰(Winsor Review) 이후에 경찰 연봉, 연금 및 근무 조건에 대한 변화도 조명하고 있다. 또한, 이러한 변화가 경찰 조직 내에서 경찰관들의 사기와 전문적인 동기에 미치는 영향을 살펴보았다. 현재의 영국 정부 정책으로 인해 점점 더 많은 수의 경험 많은 경찰관들이 경찰 조직을 떠나고 있고, 이로 인해 궁극적으로 전략적 긴급 서비스로서 치안서비스의 장기적인 탄력성이 약해질 수 있다는 점을 논의하였다.