• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.20-21
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• 2008

In the IEEE 802.16 Wireless MAN standard, the best effort service class is ranked on the lowest position in priority so that only scarce resource may be available for it. Also, the best effort service is usually assisted by a MAC scheme based on reservation ALOHA without explicit acknowledgement. However, the standard only specifies the skeleton of the MAC scheme. In this paper, we propose some rules to specify the indefinite part of the MAC scheme as well as to improve the throughput and delay performance of the MAC scheme. As generic rules for demanding and granting resource, we first propose non-gated exhaustive, gated exhaustive, non-gated limited, and gated limited demand rules, and deficient and full grant rules. Secondly, we propose grant regulation rules, identified as replacement and lifetime rules, to avoid excessive grant incurred by not giving acknowledgement. Noting the residual resource is inflated by adopting a grant regulation rule, we finally propose a rule for investing the residual resource to a subscriber station. Simulation results confirm that a combination of proposed rules improves the performance of the MAC scheme.

• The Journal of Advanced Prosthodontics
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• 제12권4호
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• pp.210-217
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• 2020

PURPOSE. The purpose of the study is to evaluate the repeatability and reproducibility of the abutment angle using a blue light scanner. MATERIALS AND METHODS. 0°, 6°, and 10° wax cast abutment dies were fabricated. Each of the silicone impression was produced using the replicable silicone. Each study die was constructed from the prepared replicable stone used for scans. 3-dimensional data was obtained after scanning the prepared study dies for the repeatability by using the blue light scanner. The prepared 3-dimensional data could have the best fit alignment using 3-dimensional software. For reproducibility, each abutment was used as the first reference study die, and then it was scanned five times per each. 3-dimensional software was used to perform the best fit alignment. The data obtained were analyzed using a nonparametric Kruskal-Wallis H test (α=.05), post hoc Mann-Whitney U test, and Bonferroni correction (α=.017). RESULTS. The repeatability of 0°, 6°, and 10° abutments was 3.9, 4.4 and 4.7 ㎛, respectively. Among them, the 0° abutment had the best value while the 10° abutment showed the worst value. There was a statistically significant difference (P<.05). The reproducibility of 0°, 6°, and 10° abutments was 6.1, 5.5, and 5.3 ㎛, respectively. While the 10° abutment showed the best value, the 0° abutment showed the worst value. However, there was no statistically significant difference (P>.05). CONCLUSION. In repeatability, the 0° abutment showed a positive result. In reproducibility, the 10° abutment achieved a positive result.

• 한국약용작물학회지
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• 제20권6호
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• pp.493-499
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• 2012

We have established adventitious root culture systems of Codonopsis lanceolata, Codonopsis pilosula and Codonopsis ussuriensis. Root segments of C. lanceolata were the best explants for induction of adventitious roots and the number of adventitious root for explant was highest on solid medium with $0.5mg/{\ell}$ NAA and produced $18.8{\pm}1.9$ roots per explant. Root segments of C. pilosula were the best explants for induction of adventitious roots and the number of adventitious root for explant was highest on solid medium with $1.0mg/{\ell}$ NAA and produced $8.5{\pm}1.8$ roots per explant. Leaf segments of C. ussuriensis were the best explants for induction of adventitious roots and the number of adventitious root for explant was highest on solid medium with $0.5mg/{\ell}$ NAA and produced $7.8{\pm}0.4$ roots per explant. In liquid culture, the best production of adventitious root (fresh weight) was obtained in 1/2 MS medium with $1.0mg/{\ell}$ NAA. This study demonstrated for the first time to produce adventitious roots in C. pilosula and C. ussuriensis.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.375-382
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• 2021

The paper introduces a model for evaluating and prioritizing mobile quality attributes and refactoring techniques through the examination of their effectiveness during the mobile application development process. The astonishing evolution of software and hardware has increased the demand for techniques and best practices to overcome the many challenges related to mobile devices, such as those concerning device storage, network bandwidth, and energy consumption. A number of studies have investigated the influence of refactoring, leading to the enhancement of mobile applications and the overcoming of code issues as well as hardware issues. Furthermore, rapid and continuous mobile developments make it necessary for teams to apply effective techniques to produce reliable mobile applications and reduce time to market. Thus, we investigated the influence of various refactoring techniques on mobile applications to understand their effectiveness in terms of quality attributes. First, we extracted the most important mobile refactoring techniques and a set of quality attributes from the literature. Then, mobile application developers from nine mobile application teams were recruited to evaluate and prioritize these quality attributes and refactoring techniques for their projects. A prioritization-based model is examined that integrates the lightweight multi-criteria decision making method, called the best-worst method, with the process of refactoring within mobile applications. The results prove the applicability and suitability of adopting the model for the mobile development process in order to expedite application production while using well-defined procedures to select the best refactoring techniques. Finally, a variety of quality attributes are shown to be influenced by the adoption of various refactoring techniques.

• International Journal of Computer Science & Network Security
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• 제24권8호
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• pp.1-13
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• 2024

Artificial intelligence (AI) describes a variety of approaches in computer applications to mimic human learning. As this technology becomes increasingly prevalent, it is inevitable that it will enter the educational environment, as both an educational tool and topic of learning. STEM education, which deals with science, technology, engineering, and math, is perhaps the most appropriate educational field in which to introduce students to this new and rapidly growing technology. In recent years, educators, AI engineers, and educational researchers have published trial results of experimental curricula implementing AI technology in student and teacher education. This systematic literature review analyzed a sample of seven such publications to identify key trends in suggested best practices for the usage of AI in STEM classrooms. The sample was analyzed for keywords using MaxQDA. The results indicated three key trends among suggested best practices. The first was that AI is best taught to students when the technology itself is the topic of education. Another trend was that simulating real world applications of AI technology was most impactful in showing students the potential, limits, and ethical implications of AI. Finally, it was found that educator's familiarity with AI is an important factor in their ability to employ it in the classroom.

• Asian-Australasian Journal of Animal Sciences
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• 제31권6호
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• pp.899-904
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• 2018

Objective: This experiment studied the effects of first feed intake time post-hatch on growth performance, nutrient apparent metabolic rate and intestinal digestive enzyme activities in broilers. Methods: Two thousand five hundred and twenty LingNan Yellow broilers were randomly allotted to seven treatments with six replicates of 60 each. The only experimental factor was the first feed intake time which was 18, 24, 30, 36, 42, 48, and 54 hours after hatching. The whole experiment lasted for 21 days. Results: During the whole period, the 30 h treatment had the best body weight and average daily gain (p<0.05), followed by the 24 h group performance optimization. Also, the 30 h group was observed to have the best apparent metabolic rate for ether extract (p<0.05) and crude protein (p<0.05) and the highest activities of amylase, lipase and trypsin in small intestine. And the 24 h group was second only to the 30 h group in terms of the above two measures. Conclusion: These results indicated that the appropriate first feeding time of LingNan Yellow broilers was 24 to 30 hours after hatching.

• Mycobiology
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• 제42권3호
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• pp.274-278
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• 2014

Penicillium georgiense was isolated from sandy beach soil from Batu Ferringhi beach, Penang Island, Malaysia. The identification was based on morphological characteristics and phylogenetic analysis of internal transcribed spacer regions and ${\beta}$-tubulin sequences. To the best of our knowledge, this is the first report of P. georgiense in Malaysia.

• Bulletin of the Korean Chemical Society
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• 제17권1호
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• pp.61-65
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• 1996

The semiempirical time-dependent Hartree-Fock PM3 calculations have been performed on three polyene systems. In order to study the nonlinear optical properties, we calculated the frequency-dependent first-, second-, and third-order polarizabilities of thiophene-, furan-, pyrrole-nitro polyene systems. The PM3 predicted average and longitudinal polarizabilties increase in the order: thiophene- > pyrrole- > furan-nitro polyene systems. The PM3 predicted limiting average second-order polarizabilities show the order: pyrrole- > furan- > thiophene-nitro polyene systems. The average and longitudinal third-order polarizabilties have the following order: pyrrole- > thiophene- > furan-nitro polyene systems. In these trends, we sugest that pyrrole group is the best donor group among the three polyene systems.

• Mycobiology
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• 제49권2호
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• pp.196-200
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• 2021

In May to July 2019, ovate-leaf atractylodes seedling and plant with Damping-off symptoms were observed in farmer field at Sangju and Mungyeong, Korea. Seven fungal isolates have been retrieved from diseased root tissue and identified as Rhizoctonia solani AG-5 based on morphological and molecular characteristics. To the best of our knowledge, this is the first report on damping-off of ovate-leaf atractylodes caused by R. solani AG-5 in South Korea.

• 한국가축번식학회지
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• 제6권1호
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• pp.36-38
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• 1982

For the purpose of identifing the reationship between the first egg day and other economic traits; egg production and egg weight, this experiment was divided 200 birds into four first egg day groups and observed egg number and egg weight every day during 11 months from 2nd December, 1979 to 31st October, 1980 at Animal farm, Yeungnam University. Birds showing 148∼155day in first egg day layed the most eggs among four groups and they produced not only 1.5g heavier eggs than the earlist first egg day group but also similar eggs compared with later matured birds. In egg production above 55g, 148∼155day group showed the best record as a 83.72% of total eggs and also the most egg mass during 11 months.