• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.256-261
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• 2011

Labor productivity is a significant factor related to control time, cost, and quality. Many researchers have developed models to define method of measuring the relationship between productivity and various constraints such as the size of working area, maximum working hours, and the crew composition. Most of the previous research has focused on estimating productivity; however, this research concentrates on estimating labor productivity and developing time and cost data for repetitive concrete pouring activity. In Korea, "Standard Estimating" only contains the average productivity data of the construction industry, and it is difficult to predict the time and cost of any particular project; hence, there are some errors in estimating duration and cost for individual activity and project. To address these issues, this research collects data, measures productivity, and develops time and cost data using labor productivity based on field conditions from the collected data. A probabilistic approach is also proposed to develop data. A case study is performed to validate this process using actual data collected from construction sites and it is possible that the result will be used as the EVMS baseline of cost management and schedule management.

• Safety and Health at Work
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• 제15권3호
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• pp.263-270
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• 2024

Background: Long-haul truck drivers (LHTD) experience disproportionately greater chronic disease risk, which may be influenced by both occupational and lifestyle factors. This study aimed to explore the multilevel factors associated with LHTD's diet and physical activity (PA). Methods: Thirty in-depth interviews were conducted with LHTD in the Southern California border region. Interview questions captured occupational and lifestyle factors relating to PA and diet at multiple levels and were analyzed using thematic analysis. Results: Emergent themes relating to both diet and PA included time constraints, attitudes and perceived beliefs, and accessibility of environments to engage in PA and healthy eating. Themes specific to PA were weather conditions and flatbed job duties. Themes specific to diet included access to refrigerators/microwaves and social interactions. Conclusion: Findings from this study can inform the development of tailored, multi-level interventions to encourage PA and healthy dietary behaviors among LHTD.

• 경영과학
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• 제11권3호
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• pp.87-102
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• 1994

Conceptual database design is an important activity because the performance of a DBMS heavily depends on the proper design of the database, and view integration is one of the most important phases of conceptual database design. During this phase, the individual views designed by separate user groups are integrated into a global view for the entire system. After the view integration, a database schema must be validated before it becomes a stable product of the design. In this paper, a methodology for view integration an validation is suggested. The individual views are modeled by entity-relationship model. The entities are integrated according to their name and domain information. After that, the relationships are merged by their constraints. We also present a methodology for checking redundant relationships which has an algorithmic description.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.709-712
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• 1996

Generating a project network of a specific construction project is very time consuming and difficult task in the field. To effectiviely automate and support the planning process, we design a case-based project planning expert system inspired by the fact a human expert project planner uses previous cases for planning a new project. A construction project case consist of its specific characteristics and the corresponding project network (i.e. project plan). Using frame based representation. we represent the project features affecting the progress network and the entities composing the project plan such as the buildings, construction methods, WBS (work breakdown structure), activities, and resources. The project planning process runs through most similar case retrieval, case adaptation, and user requirement satisfaction. We represent the construction domain knowledge for each procedure using constraints and rules. We develop the methodology for constraint-based case adaption. Case adaptation process mainly consist of activity generation/deletion and predecence constraint satisfaction, for which we develop the dynamic constraint generation method and connect user-level requirement representation the system-level network modification knowledge. The methodology is being applied to the prototype for apartment construction project planning.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제12권1호
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• pp.20-28
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• 2012

We define a language $\mathcal{RS}$, a subclass of the scheduling language $\mathcal{RS}V$ (resource constrained project scheduling with variant processes). $\mathcal{RS}$ involves the determination of the starting times for ground activities of a project satisfying precedence and resource constraints, in order to minimize the total project duration. In $\mathcal{RS}$ ground activities and two structural symbols (operators) 'seq' and 'pll' are used to construct activity-terms representing scheduling problems. We consider three different variants for formalizing the $\mathcal{RS}$-scheduling problem, the optimizing variant, the number variant and the decision variant. Using the decision variant we show that the problem $\mathcal{RS}$ is $\mathcal{NP}$-complete. Further we show that the optimizing variant (or number variant) of the $\mathcal{RS}$-problem is computable in polynomial time iff the decision variant is computable in polynomial time.

• Asian Pacific Journal of Cancer Prevention
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• 제17권sup2호
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• pp.7-9
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• 2016

In order to help smokers quit easier, China has started to provide quitline service since 2004. There are two models for Chinese quitline service-the National Quitline Model, which provides only cessation service to smokers, and the 12320 Hotline Model, which integrates cessation counseling into public health hotline service and is currently adapted in public health hotlines in 28 provinces. A protocol of 4 counseling calls is used by 12320 Hotline. Three-month abstinence rate for clients is about 20%. The fact that most smokers who attempted quit don't seek cessation help or quitline service is not well known by the public are major constraints for quitline service in China. Effective advocating campaign should be implemented to propagate quitline. Diverse protocols targeting different subpopulation will also need to be developed to better service the public.

• 아동학회지
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• 제12권2호
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• pp.78-93
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• 1991

The purpose of this study was to develop a rating scale for measuring children's temperament. The subjects were 622(324 boys and 298 girls) 3-to 7-year-old children. The temperament rating scale was composed of 50 items(4-point Liken scales) was based on mother's interview, RITQ and PTQ. The raters were the subjects' mothers. The data were analysed on dimensions of validity, reliability, and item discrimination. Statistical methods were factor analysis, ${\chi}^2$-test, and calculations of Pearson's r Cramer's V and Cronbach's $\alpha$. On validity 5 factors were extracted, which explained 84% of the total common variance. The 5 factors were named 'malleability', 'activity', 'sensitive reactivity', 'eating habits & physical constraints', 'physiological rhythmicity'. Regarding reliability, Cronbach's $\alpha$ appeared between .66 and .81 among the 5 factors. Regarding item discrimination, the degree of discrimination on all 50 items was significant and acceptable.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1047-1053
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• 2009

This paper examined an applicability of optimum algorithm to develope an electric railway pole foundation automated design system. Based on the optimization theory that considered subgrade and bearing capacity characteristics, decided an optimum section of electric railway pole foundation. In this research, Optimum algorithm used the feasible direction method in structural analysis and design efficiently. Design variables are considered geometric properties and anchor bolt area of the electric railway pole foundation as optimum construction cost. Constraints are considered settlement., overturning and activity of foundation. And, also composed flexural and shearing strength. According to optimum analysis result., optimization theory is available more economical design comparing with railway pole foundation that is constructed by current standard drawing, and applicability verified in automated design system development.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제4권3호
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• pp.353-360
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• 2004

In this paper we describe Task-Based Problem Solving Adapters (TPSAs) for modeling a humam solution (through activity-centered analysis) to a software solution (in form of computer-based artifact). TPSAs are derived from the problem solving pattern or consistent problem solving structures/strategies employed by practitioners while designing solutions to complex problems. The adapters developed by us lead toward human-centeredness in their design and underpinning that help us to address the pragmatic task constraints through a range of technologies like neural networks, fuzzy logic, and genetic algorithms. We also outline an example of applying the TPSAs to develop a working system for assisting sales engineers of an electrical manufacturing firm in preparing indent and monitoring the status of orders in the company.

• Food Science and Biotechnology
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• 제18권3호
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• pp.655-660
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• 2009

Biotechnological phytase preparations are commercially available and are currently used in animal feeding. However, thermostability constraints, low yields, and the high cost of the enzyme have limited its use. This study represents a new perspective for the food enzyme market. The research screened thermostable yeast strains for their ability to produce phytase. The screening was carried out with a gradual increase in temperature ($30-48^{\circ}C$). Sixteen strains (1 strain identified as Saccharomyces cerevisiae) maintained the ability to produce phytase at $48^{\circ}C$ and their phytase activity was confirmed using 2 phytase assay methodologies. The yeast strains tested in this study seem to be potential efficient producers of phytase, indicating a possible new source of thermostable phytase of commercial interest, particularly that from S. cerevisiae.