• 대한가정학회지
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• 제47권2호
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• pp.125-134
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• 2009

The purpose of this study was to analyze roles and duties of officials in charge of school foodservice in city, province and district 'Offices of Education'. For this purpose, the list of roles/duties of officials was developed through in-depth interviews, content analysis, and delphi technique. The list which includes 56 duty items in 8 dimensions was used for developing a questionnaire. A total of 282 questionnaires from 102 Offices of Education were used for the analysis. The school foodservice officials regarded 'budget management', 'facilities & labor management', 'developing long-term plan', and 'inspection & evaluation' as important. 'Education and research' and ‘management of nutrition, diet, and food materials' showed higher level of importance and need for support compared to its frequencies of work. There was no significant difference among city, provincial, and district Offices of Education on the levels of importance for each area/category. However, 'Officials in the District Offices of Education' needed more support in the area/category of 'facility & labor management'(p < .01). In addition, there was a significant difference between actual and ideal proportion of work in 'education & research'(p < .001), 'management of nutrition, diet and food'(p < .01), 'other supports for school foodservice'(p < .05) amongst the officials in 'City & Province Offices of Education'. For 'officials in the District Offices of Education', actual and ideal proportion of work was different in 'planning & coordination'(p < .01), 'school foodservice program management'(p < .001), 'education & research' (p < .001), 'management of nutrition, diet and food materials'(p < .001), and 'budget management'(p < .001). The results of this study showed that the areas of 'budget management', 'facility & labor management', and 'developing long-term plan', inspection & evaluation' needed more support for 'City & Province Offices of Education'. 'Officials in the District Offices of Education' also needed more support in the areas of 'budget management' and 'facility & labor management'.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권10호
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• pp.2731-2749
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• 2012

Sybil attack has been proved effective in mitigating the P2P botnet, but the impacts of some important parameters were not studied, and no model to estimate the effectiveness was proposed. In this paper, taking Kademlia-based botnets as the example, the model which has the upper and lower bound to estimate the mitigating performance of the Sybil attack is proposed. Through simulation, how three important factors affect the performance of the Sybil attack is analyzed, which is proved consistent with the model. The simulation results not only confirm that for P2P botnets in large scale, the Sybil attack is an effective countermeasure, but also imply that the model can give suggestions for the deployment of Sybil nodes to get the ideal performance in mitigating the P2P botnet.

• Child Health Nursing Research
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• 제11권3호
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• pp.330-339
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• 2005

Purpose: This study was done to identify menstrual discomfort and dietary habits, and factors related to the menstrual discomforts. Method: Participants were 320 female middle school students in G city. The Menstrual Discomfort Questionaire(MDQ) and dietary habit lists were used as tools. Results: Factors related to MDQ were found to be the VAS scores (r=.361, p=.002), a mount of menstrual bleeding (r=.131, p=.019), height (r=.134, p=.016), adequacy of meal time (t=7.19, p=.008), consumption of milk & milk products (F=3.20, p=.042) and, hot, salty & irritant foods (f=8.01, p=.000), eating more than 3 kinds of side-dishes with each meal (F=8.32, p=.000), and various protein foods (F=5.15, p=.006). In stepwise regression, 4 variables (VAS scores, height, hot, salty & irritant foods, more than 3 kinds of side-dishes with each meal) explained $20.3\%$ of the variance in the total MDQ scores. Conclusion: Reduction of hot, salty & irritant foods and having more than 3 side-dishes with each meal would be effective in menstrual discomfort management. As well, good and, balanced dietary habits should be encouraged for early adolescent girls. To keep up with the ideal dietary habits, nutritional education & counseling should be continued. In a further study, a replication study with larger samples and more specified nutritional assessment are recommended.

• Journal of Korean Vacuum Science & Technology
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• 제6권2호
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• pp.58-61
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• 2002

Photoluminescence up-conversion in semiconductor heterostructures is a phenomenon in which luminescence occurs at energies higher than that of the excitation photons. It has been observed in many semiconductor heterostructure systems, including InP/AnALAs, CdTe/CdMgTe, GaAs/ordered-(Al)GalnP, GaAs/AIGaAs, and InAs/GaAs. In this wort, GaAs/AIGaAs heterostructures are used as a model system to study the mechanism of the up-conversion process. This system is ideal for testing different models because the band offsets are quite well documented. Different heterostructures are designed to study the effect of disorder on the up-converted luminescence efficiency. In order to study the roles of different types of carriers, the effect of doping was investigated. It was found that the up-converted luminescence is significantly enhanced by p-type doping of the higher-band-gap material.

• 호남수학학술지
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• 제42권2호
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• pp.345-358
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• 2020

In this paper, we study the concepts of Wijsman lacunary invariant convergence, Wijsman lacunary invariant statistical convergence, Wijsman lacunary ${\mathcal{I}}_2$-invariant convergence (${\mathcal{I}}^{{\sigma}{\theta}}_{W_2}$), Wijsman lacunary ${\mathcal{I}}^*_2$-invariant convergence (${\mathcal{I}}^{\ast}^{{\sigma}{\theta}}_{W_2}$), Wijsman p-strongly lacunary invariant convergence ([W₂N_σθ]_p) of double sequence of sets and investigate the relationships among Wijsman lacunary invariant convergence, [W₂N_σθ]_p, ${\mathcal{I}}^{{\sigma}{\theta}}_{W_2}$ and ${\mathcal{I}}^{\ast}^{{\sigma}{\theta}}_{W_2}$. Also, we introduce the concepts of ${\mathcal{I}}^{{\sigma}{\theta}}_{W_2}$-Cauchy double sequence and ${\mathcal{I}}^{\ast}^{{\sigma}{\theta}}_{W_2}$-Cauchy double sequence of sets.

• 한국정보처리학회논문지
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• 제7권6호
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• pp.1778-1784
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• 2000

We consider the weighted shortest path updating problem, that is, the problem to reconstruct the weighted shortest paths in response to topology change of the network. This appear proposes a distributed algorithms that reconstructs the weighted shortest paths after several processors and links are added and deleted. its message complexity and ideal-time complexity are O(p$^2$+q+n') and O(p$^2$+q+n') respectively, where n' is the number of processors in the network after the topology change, q is the number of added links, and p is the total number of processors in he biconnected components (of the network before the topology change) including the deleted links or added links.

• 대한수학회논문집
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• 제35권3호
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• pp.723-731
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• 2020

The purpose of this paper is to study the structure of quotient rings R/P where R is an arbitrary ring and P is a prime ideal of R. Especially, we will establish a relationship between the structure of this class of rings and the behavior of derivations satisfying algebraic identities involving prime ideals. Furthermore, the characteristic of the quotient ring R/P has been determined in some situations.

• 대한수학회지
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• 제39권4호
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• pp.611-620
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• 2002

The aim of the Paper is to Obtain information about the flat covers and minimal flat resolutions of Artinian modules over a Noetherian ring. Let R be a commutative Noetherian ring and let A be an Artinian R-module. We prove that the flat cover of a is of the form $\prod_{p\epsilonAtt_R(A)}T-p$, where $Tp$ is the completion of a free R$_{p}$-module. Also, we construct a minimal flat resolution for R/xR-module 0: $_AX$ from a given minimal flat resolution of A, when n is a non-unit and non-zero divisor of R such that A = $\chiA$. This result leads to a description of the structure of a minimal flat resolution for ${H^n}_{\underline{m}}(R)$, nth local cohomology module of R with respect to the ideal $\underline{m}$, over a local Cohen-Macaulay ring (R, $\underline{m}$) of dimension n.

• 대한수학회논문집
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• 제20권4호
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• pp.645-648
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• 2005

Let K be a Galois extension of a field F with G = Gal(K/F). Let L be an extension of F such that $K\;{\otimes}_F\;L\;=\; N_1\;{\oplus}N_2\;{\oplus}{\cdots}{\oplus}N_k$ with corresponding primitive idempotents $e_1,\;e_2,{\cdots},e_k$, where Ni's are fields. Then G acts on $\{e_1,\;e_2,{\cdots},e_k\}$ transitively and $Gal(N_1/K)\;{\cong}\;\{\sigma\;{\in}\;G\;/\;{\sigma}(e_1)\;=\;e_1\}$. And, let R be a commutative F-algebra, and let P be a prime ideal of R. Let T = $K\;{\otimes}_F\;R$, and suppose there are only finitely many prime ideals $Q_1,\;Q_2,{\cdots},Q_k$ of T with $Q_i\;{\cap}\;R\;=\;P$. Then G acts transitively on $\{Q_1,\;Q_2,{\cdots},Q_k\},\;and\;Gal(qf(T/Q_1)/qf(R/P))\;{\cong}\;\{\sigma{\in}\;G/\;{\sigma}-(Q_1)\;=\;Q_1\}$ where qf($T/Q_1$) is the quotient field of $T/Q_1$.

• Carbon letters
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• 제13권2호
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• pp.61-72
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• 2012

Dye removal from waste water via adsorption by activated carbons (ACs) developed from agricultural wastes represents an ideal alternative to other expensive treatment options. Physical and chemical ACs were prepared from rice husks. The textural properties of the ACs were characterized by Brunauer-Emmett-Teller-$N_2$ adsorption and scanning electron microscopy. The chemistry of the carbon surface was investigated by Fourier transform infrared spectroscopy, base and acid neutralization capacities, pH of the active carbon slurry, and $pH_{pzc}$. The adsorption capacities of the ACs for the basic dye (methylene blue) and acid dye (acid green 25) were determined using parameters such as contact time, pH, and temperature. NaOH-ACs showed the highest surface area and total pore volume, whereas steam-ACs showed the lowest ones.