• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.295-302
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• 2011

Ubiquitous is an information communication environment which peoples could connect on network without being conscious of the network and computer condition at anytime and anywhere. Presently, advanced technology, digital cities and eco-friendly cities using Ubiquitous technology are being focused through out the world. As recent information industry and communication technology have developed remarkably, studies on intelligent structures and structural maintenance methods by combining a general idea of connecting all objects on network by interpolating computers which is called Ubiquitous Computing, and USN(Ubiquitous Sensor Network) are being attempted. In this paper, a basic experiment on penetration of RF(Radio Frequency) sensor nodes using an experimental sample setting concrete and reinforcing bar as variables is studied to estimate the possibility of applying wireless sensor networks in structures. The spring of reinforcing bars, concrete thickness, intensity of radio frequency were set up as variables, transmitting and receiving distance were checked vertically and horizontally. Moreover, Spectrum Analyzer was used for checking the magnitude of the frequency used in order to measure the reduction of radio wave exactly. The radio wave reduction was numerically analyzed, and the influence of the wavelength was analysed as well. As a result, the penetration depth in concrete without reinforcing bars was 45cm, and in reinforced concretes which reinforcing bars placed at spacing of 5cm and 15cm, the penetration depth were 37cm and 45cm each. No influence on radio wave penetration depth were found when the spacing of reinforcing bars in the reinforced concrete structures becomes over 15cm.

• Journal of Science and Technology Studies
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• v.2 no.2 s.4
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• pp.145-189
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• 2002

This paper explores into the potential contribution of welfare science and technology(WST) to meeting the challenges of ageing. Drawing on the literature about gerontechnology, this paper considers the application of scientific knowledge for welfare of an aging population. WST for the improvement of the daily functioning of the elderly people can not only prevent, delay or compensate for the declines or impairments of coginitive and physical functions (by assistive technology) but also enhance personal ability to overcome problems either by supporting the person's abilities (by supportive technology) or by changing the environment (by public welfare technology). This paper draws attention to a paradigm change in the conceptualization of disability and its ramifications for the role of technology and aging. A range of approaches such as Barrier-Free design, Universal Design points to new directions of WST in which products and services are devised to improve the quality of life for all people, and hence enhancing the socio-economic vitality. It is suggested that the future of welfare science and technology will be based in large measure on its goal to reduce or prevent individual and structural lag in the relationships between people and their environments. Addressing issues of the broader physical and social environment will emphasize the goal of prevention and the view that environmental needs for aging population are changing over time.

• The Journal of Korean Academy of Prosthodontics
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• v.18 no.1
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• pp.15-35
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• 1980

The purpose of this study was to investigate stresses in the various components of fixed partial dentures restoring the posterior teeth of the lower jaw, and to measure quantitatively the effects of certain modifications in structural design on the stresses in the restorations using two-dimensional photoelasticity. Two-dimensional photoelastic methods were used in this study. Several models of fixed partial dentures were constructed. Shoulder less margins and anatomic occlusal reduction were incorporated in Model 1. Rounded shoulders and flat occlusal reduction were incorporated in Model 2, while Model 3 was a cantilever fixed partial denture. Other similar fixed partial dentures were constructed with V and U notches deliverately included in the region of the fixed joints for comparative reasons. The birefringent materials used in this study were PSM-1 and PSM-5 in standard sheets. PSM-1 was used for constructing the substructure, and PSM-5 was used in making the components of the fixed partial dentures. The two materials were used in the construction of composite photoelastic models. Improved artificial stone was used to represent dental cement in luting the composite photoelastic models. Static loading procedures were used at preplanned sites to represent occlusal loads in the mouth. 35 mm color and B/W film were used to record isochromatics in accordance with photoelastic procedures. Data reduction was performed using the grid method, which helped in, the mathematical integration procedure (Shear difference method) to separate the principal stresses. The results were as follows. 1. Fixed partial dentures do not function in bending as a symmetrical beam. Alternate areas of tension and compression were demonstrated when multiple contact loading was used. 2. The weakest part in posterior fixed partial dentures is the fixed joint. 3. (1) Models I and modified Model I were loaded on the pontic using a 50 pound vertical static load. The shear stress near the posterior fixed joint in Model 1 (U notches) was+129.4 p.s.i., and at the same fixed joint in modified Model 1 (V notches) was+239.4 p.s.i. The concentration of stress in fixed joint was reduced by 50% when U notches replaced the V notches. (2) Modified Model 2 was loaded using a multiple contact loader at a total load of 125 pounds. The difference between the principal stresses (${\sigma}_1-{\sigma}_2$), shear stress, at the V notches was+600 p.s.i., and at the U notches was+3l7 p.s.i. The shear stress was reduced by 50% when U notches replaced the V notches. V-grooves at the fixed joints should be avoided, and should be replaced by regular shaped U-grooves. 4. Cantilever fixed partial dentures had much higher stresses at the fixed joint than fixed partial dentures that were attached at both ends.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.517-527
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• 2010

The purpose of this study was to investigate the causal relationship among perceived value, satisfaction and revisit intention for visitors of the Korea National Arboretum. Three hundred respondents were selected by quota sampling, and well-known measurement scales utilized in marketing field were adopted in order to measure three variables with some modification to apply for arboretum visitors. Results of structural equation model showed that perceived value affected visitors' satisfaction, which in turn influenced revisit intention. Specifically, "emotional value" had the most significant influence on satisfaction, followed by "value for money" and "novelty value"; however, "social value" was not an influential construct. Based on calibration results, several strategies were suggested for the effective management. Authors advised that (a)improvement of measurement scale of value, (b)inclusion of self-congruity as antecedent variable to satisfaction, (c)changing revisit intention to word-of-mouth communication as a post-purchase behavioral intention, and (d)implementation of market segmentation should be considered for future research.

• Korean Institute of Interior Design Journal
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• v.24 no.5
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• pp.108-116
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• 2015

This study intends to research the spatial characteristics of Asian interim housing that accommodates sufferers pro tempore after disasters. The scope of this research covers the interim spaces used for housing people after natural disasters that occurred in Asia for the past fifteen years. Within this scope, literature review was conducted as the basis to derive the characteristics and environmental elements of interim housing, which provided the criteria to compare and evaluate cases of interim housing along with characteristic elements required of interim housing found in previous studies. According to literature review, interim housing can be classified by life-span, region, economy, climate, type, number of household, square measure, residential cost, structure/material, and service life. Within the scope of the present research, literature review showed a total of twenty-eight cases of interim housing in fifteen countries revealing a high rate of disaster occurrence in the subtropic and tropic climate of Southeast Asia. A great percentage of interim housing was used for long-term stay of over a year. The structure of interim housing varied from lightweight steel, wooden, masonry, membrane, to traditional structure and the type were divided into temporary shelter, transitional housing, temporary housing, and permanent housing. Followed by literature review, the characteristics required of post-disaster interim housing were analyzed based on previous research and case studies. The characteristics of interim housing can be divided into environmental, technological, and socio-cultural ones. Sub-characterical items according to such division include amenity, health, surroundings, structure, convenience, eco-friendliness, safety, communication, and locality. As a result of evaluation, most items met the required characteristics of interim housing, while technological characteristics such as structure and convenience varied with the types of interim housing and appeared even unnecessary in some cases. According to analysis, amenity is maintained through the structural and material characteristics of interim housing and is also facilitated by increasing number of infrastructure such as educational, sanitary, and convenience facilities provided by the governmental and organizational bodies. It is expected that this study will be utilized as preliminary data for follow-up studies that improve the environment of post-disaster interim housing suitable for domestic circumstances in environmental, technological, and socio-cultural respects.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.89-93
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• 2018

High sodium dietary habits may cause various diseases, thereby threatening the public health. Various efforts have been made to control high sodium use in diets, but few studies have been conducted on health communication efforts to modify such habits. This study looks for suggestions for diet improvement education by examining whether or not high sodium dietary habits can be predicted by a consumer's perception on the threat and controllability of high sodium diets. In this study, a questionnaire was developed to measure the severity, vulnerability, efficiency, efficacy, and behavioral tendencies of the consumer, which were subscales of the protective motivation theory. The questionnaire was given to university students and their families in Chungnam Province. The results of a statistical analysis were as follows: First, more young people preferred high-sodium diets than older people. Second, the correlation analysis showed that older people knew that they were vulnerable to the negative effects of high sodium diets, but they would not change their dietary habits until they were confident that they could control the high-sodium diet. Third, the structural model analysis showed that the higher the coping perception was, the lower was the tendency to consume a high-sodium diet. These results suggest that in the effort to reduce high-sodium diets, it is more effective to provide viable information and improve efficacy.

• Journal of Distribution Science
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• v.13 no.1
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• pp.93-103
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• 2015

Purpose - This study plans to adopt a more sophisticated approach toward service recognition by customers in general supermarkets in order to revise the service quality measurement methods that suit the context of Korean distribution channels. In particular, in general supermarkets, where much of the shopping process is in the form of self-service, there is high reliance on the service recognized by the consumers; therefore, it is highly likely that consumers would make their purchasing decisions based on their recognition of service quality or guarantees. It also utilized service quality elements of a basic level in the KD-SQS development model in order to indicate that the quality recognized by consumers impacts their loyalty to the stores with financial value and abstract value. Research design, data, and methodology - The study suggested a theoretical model comprising 13 hypotheses on relations between theoretic variables, and conducted surveys with consumers using discount stores in Seoul and Gyunggi Metropolitan area in order to verify the hypotheses, while using SPSS 20.0, AMOS 21.0 as the verification program. The survey sheets used amounted to 332, and a structural equation model was used to analyze the reliability and validity of constituent elements and to verify the suggested hypothesis. Therefore, this study analyzes the interrelations between service quality and guarantee factors in the distribution channel and their relations with the loyalty to stores as a dependent variable. Results - First, the results of the hypotheses tests helped identify the relations between service quality, service guarantees, service value, and customer loyalty, providing an opportunity to define the relations between constituent elements. In particular, service convenience in service quality has no impact on financial values. Further, stores' service policy had no impact on abstract values. Service recognition by service convenience has an impact on abstract values such as good image, comfort, and usability, while mileage systems promote financial values for consumers. In order to improve consumer values in service quality and values, general supermarkets should improve their service convenience, membership, and mileage programs using various strategies. Conclusion - In order to improve consumer values in service quality and values, general supermarkets should improve their service convenience, membership, and mileage programs using various strategies. Further, as service guarantee systems have a significant and direct impact on customer loyalty, rather than customer value recognition, service guarantees should be used to encourage customers to re-visit the stores. Finally, this study applied the findings of preceding studies in terms of service quality measurement; it had limitations in referencing preceding studies in a comprehensive manner. It also had limits in expanding upon various preceding studies because it was difficult to apply new measurement tools due to the lack of service quality measurement tools for general supermarkets. Therefore, it is necessary to conduct more studies on service quality to measure service quality and develop measurement tools by incorporating various industry characteristics.

• FLOWER RESEARCH JOURNAL
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• v.19 no.1
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• pp.68-76
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• 2011

This study was conducted to investigate customer taste related to satisfaction of a baby's first birthday party and re-visit of venues. General characteristics of customers were similar in male and female or the married and the unmarried. Mainstream age of respondents was from in their 20's to 30's. Among them, the number of university graduates were the largest in education level. Theoretical model was composed with seven significant variables of design style and composition and design harmony and color sense for flower decoration, accessibility, facility, service and price, satisfaction, and intention of re-visit based on the result of analysis on these factors. Exploratory factor analysis was performed using SPSS 14.0K. Structural equation modeling(SEM) for simultaneous measure of path coefficient in all casualty of study model, measurement model of AMOS 7.0 for evaluation of validity, and reliability and factor analysis method using technical statistics, frequency analysis, and Cronbach's Alpha for data analysis were used. The result of hypothesis verification showed that design style and composition was the most significant item in satisfaction of parameter and it was followed by design harmony and color sense. While service and price had positive effect on satisfaction, accessibility and facility had no relation to it. It means that the most crucial variable was a flower decoration in planning and representation of the celebration of baby's first birthday. In conclusion, the finding of this study suggests that the effective utilization of these variables will contribute to the enhancement of satisfaction affecting improvement service and price or intention of re-visit.

• Structural Engineering and Mechanics
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• v.50 no.5
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• pp.589-603
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• 2014

Expressions for determining the value of the impact force as reported in the literature and incorporated into code provisions are essentially quasi-static forces for emulating deflection. Quasi-static forces are not to be confused with contact force which is generated in the vicinity of the point of contact between the impactor and target, and contact force is responsible for damage featuring perforation and denting. The distinction between the two types of forces in the context of impact actions is not widely understood and few guidelines have been developed for their estimation. The value of the contact force can be many times higher than that of the quasi-static force and lasts for a matter of a few milli-seconds whereas the deflection of the target can evolve over a much longer time span. The stiffer the impactor the shorter the period of time to deliver the impulsive action onto the target and consequently the higher the peak value of the contact force. This phenomenon is not taken into account by any contemporary codified method of modelling impact actions which are mostly based on the considerations of momentum and energy principles. Computer software such as LS-DYNA has the capability of predicting contact force but the dynamic stiffness parameters of the impactor material which is required for input into the program has not been documented for debris materials. The alternative, direct, approach for an accurate evaluation of the damage potential of an impact scenario is by physical experimentation. However, it can be difficult to extrapolate observations from laboratory testings to behaviour in real scenarios when the underlying principles have not been established. Contact force is also difficult to measure. Thus, the amount of useful information that can be retrieved from isolated impact experiments to guide design and to quantify risk is very limited. In this paper, practical methods for estimating the amount of contact force that can be generated by the impact of a fallen debris object are introduced along with the governing principles. An experimental-calibration procedure forming part of the assessment procedure has also been verified.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.113-120
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• 2021

As a result, the interaction between personal motivation and class type is not significant. On the other hand, the interaction between social motivation and class type is significant and overall online class increases engagement with educational issues. In particular, the group with low social motivation showed greater change than the group with high social motivation, so online education seems to be more effective in the group with low social motivation. It means that by stimulating students' social motivation rather than personal motivation, the effectiveness of online education can be enhanced, and it can lead to education outcomes - behavioral changes and attitudes of learners. In order to revitalize social motivation in the intensely personal space of online, it is necessary to activate social communication methods such as SNS, and development of interpersonal issues and learning materials would be more efficient. In order to derive more specific results, it is necessary to measure the level of prior knowledge and involvement of the participants in class, and to comprehensively investigate and analyze the state of learners before and after class through more variables. Finally, in order to increase the reliability of the research results, it is necessary to clearly prove it through the establishment of a structural model.