• Bulletin of the Korean Mathematical Society
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• v.50 no.6
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• pp.1887-1903
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• 2013

We continue the study of McCoy condition to analyze zero-dividing polynomials for the constant annihilators in the ideals generated by the coefficients. In the process we introduce the concept of ideal-${\pi}$-McCoy rings, extending known results related to McCoy condition. It is shown that the class of ideal-${\pi}$-McCoy rings contains both strongly McCoy rings whose non-regular polynomials are nilpotent and 2-primal rings. We also investigate relations between the ideal-${\pi}$-McCoy property and other standard ring theoretic properties. Moreover we extend the class of ideal-${\pi}$-McCoy rings by examining various sorts of ordinary ring extensions.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1146-1152
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• 2005

Graft copolymers were synthesized from methylcellulose(MC) and acrylic acid(AA) with active carboxyl groups in the presence of potassium persulfate($K_2S_2O_8$) initiator to enhance adsorption capacity of toxic heavy metal such as $Pb^{2+}$ and $Cu^{2+}$ from wastewater. The resulting grafted copolymers(MC-g-AA/PAA) were mixture of the graft copolymers from MC and AA(MC-g-AA) and polyacrylic acid homopolymers(PAA). The degree of palling was increased with rising concentration of monomer and initiator under the reaction conditions at $60^{\circ}C$, 3 hrs. The water insoluble property of MC-g-AA showed more than 19.7% degree of grafting. So that it could be an adsorbent of heavy metals. Adsorption characteristics of the MC-g-AA were evaluated depending on the degree of grading, pH of wastewater, adsorption time, dosage of MC-g-AA and concentration of heavy metals in the different conditions. Degree of grafting, and initial concentration of heavy metal ions increased, the adsorption amount of $Pb^{2+}$ and $Cu^{2+}$ increased, but added MC-g-AA increased, the adsorption amount per unit weight of $Pb^{2+}$ and $Cu^{2+}$ decreased. The MC-g-AA showed the high $Pb^{2+}$ and $Cu^{2+}$ adsorption amount in the range pH $4{\sim}6$. Also all of $Pb^{2+}$ and $Cu^{2+}$ ions reached in adsorption equilibrium in neighborhood 4 hours. The adsorption of heavy metals described by Freundlich isotherm, it was determined the value of l/n of $Pb^{2+}$ and $Cu^{2+}$ that 0.4294 and 0.3453, respectively.

• The Korean Journal of Pharmacology
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• v.27 no.1
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• pp.53-67
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• 1991

The characteristics and differences between DMPP and McN-A-343 on the secretory effect of catecholamines(CA) were studied in the isolated perfused rat adrenal glands. DMPP(100 uM) and McN-A-343(100 uM) perfused into an adrenal vein of the gland casued significant increases in CA secretion. On molar basis the secretory effect of McN-A-343 was about one fifth as potent as that of DMPP. Tachyphylaxis to releasing effects of CA evoked by DMPP and McN-A-343 was not observed by repeated perfusion of these agents. The DMPP-evoked CA secretion was significantly inhibited by pretreatment with chlorisondamine, desipramine and profusion of $Ca^{2+}-free$ Krebs solution containing EGTA, while it was not affected by pirenzepine, ouabain and physostigmine. However, pretreatment with atropine rather enhanced CA release by DMPP. The releasing effect of CA induced by McN-A-343 was markedly depressed by pretreatment with atropine, pirenzepine, chlorisondamine, physostigmine, and perfusion of $Ca^{2+}-free$ medium plus EGTA but was not influenced by desipramine, except for the case of ouabain which clearly potentiated CA release by McN-A-343. These experimental results suggest that both DMPP and McN-A-343 cause greatly secretion of CA from the isolated perfused rat adrenal glands by a calcium-dependent exocytotic mechanism. The secretory effect of DMPP is due to the stimulation of cholinergic nicotinic receptors and the secretion by McN-A-343 via activation of selecive $M_{1}-muscarinic$ receptors in the adrenal gland. It is also thought that the DMPP-evoked secretory effect is much greater than McN-A-343-induced effect.

• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.1-7
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• 2020

Deep neural networks(DNN), which are used as approximation functions in reinforcement learning (RN), theoretically can be attributed to realistic results. In empirical benchmark works, time difference learning (TD) shows better results than Monte-Carlo learning (MC). However, among some previous works show that MC is better than TD when the reward is very rare or delayed. Also, another recent research shows when the information observed by the agent from the environment is partial on complex control works, it indicates that the MC prediction is superior to the TD-based methods. Most of these environments can be regarded as 5-step Q-learning or 20-step Q-learning, where the experiment continues without long roll-outs for alleviating reduce performance degradation. In other words, for networks with a noise, a representative network that is regardless of the controlled roll-outs, it is better to learn MC, which is robust to noisy rewards than TD, or almost identical to MC. These studies provide a break with that TD is better than MC. These recent research results show that the way combining MC and TD is better than the theoretical one. Therefore, in this study, based on the results shown in previous studies, we attempt to exploit a random balance with a mixture of TD and MC in RL without any complicated formulas by rewards used in those studies do. Compared to the DQN using the MC and TD random mixture and the well-known DQN using only the TD-based learning, we demonstrate that a well-performed TD learning are also granted special favor of the mixture of TD and MC through an experiments in OpenAI Gym.

• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1269-1282
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• 2010

We in this note consider a new concept, so called $\pi$-McCoy, which unifies McCoy rings and IFP rings. The classes of McCoy rings and IFP rings do not contain full matrix rings and upper (lower) triangular matrix rings, but the class of $\pi$-McCoy rings contain upper (lower) triangular matrix rings and many kinds of full matrix rings. We first study the basic structure of $\pi$-McCoy rings, observing the relations among $\pi$-McCoy rings, Abelian rings, 2-primal rings, directly finite rings, and ($\pi-$)regular rings. It is proved that the n by n full matrix rings ($n\geq2$) over reduced rings are not $\pi$-McCoy, finding $\pi$-McCoy matrix rings over non-reduced rings. It is shown that the $\pi$-McCoyness is preserved by polynomial rings (when they are of bounded index of nilpotency) and classical quotient rings. Several kinds of extensions of $\pi$-McCoy rings are also examined.

• Korean journal of medical education
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• v.30 no.4
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• pp.317-326
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• 2018

Purpose: The study examines changes in students' self-assessment of their general communication (GC) and medical communication (MC) competencies, as well as perceptions of MC concepts. Methods: Participants included 108 second year medical students enrolled at a Korean medical school studying an MC curriculum. It was divided into three sections, and participants responded to questionnaires before and after completing each section. To assess perceived GC and MC competency, items based on a 7-point Likert scale were employed; a single open-ended item was used to examine students' perceptions of MC. Statistical analysis was conducted to gauge GC and MC competency, whereas semantic network analysis was used to investigate students' perceptions of MC. Results: Students perceived their GC competency to be higher than MC. Perceived MC competency differed significantly across the three sections, whereas no differences were found for GC. There were no statistically significant differences after completing the curriculum's second and third sections; however, the vocabulary students used to describe MC concepts became more scholarly and professional. In the semantic networks, the link structure between MC-related words decreased in linearity and looseness, becoming more complex and clustered. The words 'information' and 'transfer' proved integral to students' perceptions; likewise, 'empathy' and 'communication' became closely connected in a single community from two independent communities. Conclusion: This study differed from prior research by conducting an in-depth analysis of changes in students' perceptions of MC, and its findings can be used to guide curriculum development.

• Bulletin of the Korean Mathematical Society
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• v.48 no.1
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• pp.23-33
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• 2011

Extending the notion of McCoy rings, we introduce the class of McCoy modules. Over a given ring R, it contains the class of Armendariz modules (over R). Some properties of this class of modules are established, and equivalent conditions for McCoy modules are given. Moreover, we study the relationship between a module and its polynomial module. Several known results relating to McCoy rings can be obtained as corollaries of our results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.291-297
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• 2007

This study was conducted to investigate the hepatic detoxification effect of microcluster-water (McW). Animal experiments were divided into 4 groups: distilled water intake group (DC), distilled water intake-bromobenzene treated group (DB), McW intake group (MC), and McW intake-bromobenzene treated group (MB). There were no significant differences in alanine aminotransferase and aspartate aminotransferase activities between DC and MC groups, but the activities in MB group were significantly (p<0.05) lower than those in DB group. No apparent changes of aniline hydrolase activity were shown in all experimental groups, while glutathione S-transferase activity in MC and MB groups was higher than that in DC and DB, respectively. The content of hepatic lipid peroxide in DC group was similar to that of MC group. In addition, the contents in DB and MB groups were significantly (p<0.05) increased than that of DC group. The increasing rate in MB group was lower than that of DB group. Also, the electron donating activity of McW was significantly (p<0.05) higher than that of distilled water. From these results, it could be suggested that McW has the possibility of having detoxification effect of bromobenzene induced hepatic injury by increasing glutathione S-transferase, which is known as a kind of hepatiic detoxification enzyme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12A
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• pp.1319-1332
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• 2004

Multicarrier direct sequence code-division multiple access CDMA(MC DS-CDMA) is an attractive technique for achieving high data rate transmission even if the potentially large peak-to-average power ratio(PAPR) is an important factor for its application. On the other hand, code select CDMA(CS-CDMA) is an attractive technique with constant amplitude transmission of multicode signal irregardless of subchannels by introducing code selection method. In this paper we propose a new multiple access scheme based on the combination of MC DS-CDMA and CS-CDMA. Proposed scheme, which we called MC CS-CDMA, includes the sutclasses of MC DS-CDMA and CS-CDMA as special cases. The performance of this system is investigated for multipath Sequency selective fading channel and maximal ratio combining with rake receiver. In addition the PAPR of proposed system is compare with that of both MC BS-CDMA and CS-CDMA. Simulation results show that proposed system improves PAPR reduction than MC DS-CDMA at the expense of the complexity of receiver and the number of available non. Also, the numerical result shows that the proposed system is better performance than MC DS-CDMA due to the increasing processing gain and the number of time diversity gain.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.254-259
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• 2004

This experiment was conducted to investigate the effects of supplemented diets with Malty Culture(MC) during lactation on sow and litter performance. Eighteen lactating sows were randomly assigned to three dietary treatments(basal diet, basal diet+MC0.5%, basal+MCl.0%). Average daily feed intake of sow was not affected by dietary treatments with treatment means ranging from 4.49 to 4.58kg(p>0.62). All sows lost their backfat thickness during lactation with no difference among the treatments(p>0.25). Fecal moisture was similar for sows fed the control and MC treatments with 70% moisture content. The growth rate of piglets was not significant difference among the treatments ranging from 47 to 48kg. Day to estrus postweaning was not affected by supplementation of MC with treatment means ranging from 5 to 7 days. There was not significant difference in the milk production(i.e, 8.9kg/d for control, 9.18kg/d for MC0.5 and 9.20kg/d for MC1.0). Survivability of piglet was affected by feeding added MC during lactation. There was no significant difference in the digestibility of DM, but the digestibility of N tended to increase in sows fed the MC0.5 and MC1.0 supplemented diets compared to the basal diet(linear effect, p<0.10; quadratic effect. p<0.08). Digestibility of P tended to increase by the treatment of supplemented MC. However, there was no significant difference among the treatments. In conclusion, the results of experiment suggest that lactation diet of supplemented MC could be a beneficial feeding for digestibility in sow and litter performance.