• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.579-587
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• 2015

The purpose of this study is to investigate how Korean learners perceive English vowels and further to test SLM which claims that new L2 vowel categories are more easily acquired than similar L2 vowel categories. Twenty Korean learners participated in English-to-Korean mapping test and English vowel identification test with target vowels /i, ɪ, u, ʊ, ɛ, æ/. The result revealed that Korean participants mapped the English pairs /i/-/ɪ/ and /u/-/ʊ/ onto single Korean vowel /i/ and /u/, respectively. in addition, both of English /ɛ/ and /æ/ were simultaneously mapped onto Korean /e/ and /ɛ/. This indicated that the Korean participants seemed to have perceptual difficulty for the pairs /i-ɪ/, /u-ʊ/, and /ɛ-æ/. The result of the forced-choice identification test showed that the accuracy of /ɪ, ʊ, æ/(ɪ: 81.3%, ʊ: 62.5%, æ: 60.0%) was significantly higher than that of /i, u, ɛ/(i: 28,8%, u: 28.8%, ɛ: 32.4%). Thus, the claim of SLM is confirmed given that /ɪ, ʊ, æ/ are new vowel categories whereas /i, u, ɛ/ are similar vowel categories. Further, the conspicuously low accuracy of the similar L2 vowel categories /i, u, ɛ/ was accounted for by over-generalization whereby the Korean participants excessively replaced L2 similar /i, u, ɛ/ with L2 new /ɪ, ʊ, æ/ as the participants were learning the L2 new vowel categories in the process of acquisition. Based on the findings this study, pedagogical suggestions are provided.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.111-114
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• 2010

Purpose: There has been recent interest in the radioactivity uptake and image acquisition of radioactivity concentration. The degree of uptake is strongly affected by many factors containing $^{18}F$-FDG injection volume, tumor size and the density of blood glucose. Therefore, we investigated how radioactivity uptake in target influences 2D or 3D image analysis and elucidate radioactivity concentration that mediate this effect. This study will show the relationship between the radioactivity uptake and 2D,3D image acquisition on radioactivity concentration. Materials and Methods: We got image with 2D and 3D using 1994 NEMA PET phantom and GE Discovery(GE, U.S.A) STe 16 PET/CT setting the ratio of background and hot sphere's radioactivity concentration as being a standard of 1:2, 1:4, 1:8, 1:10, 1:20, and 1:30 respectively. And we set 10 minutes for CT attenuation correction and acquisition time. For the reconstruction method, we applied iteration method with twice of the iterative and twenty times subset to both 2D and 3D respectively. For analyzing the images, We set the same ROI at the center of hot sphere and the background radioactivity. We measured the radioactivity count of each part of hot sphere and background, and it was comparative analyzed. Results: The ratio of hot sphere's radioactivity density and the background radioactivity with setting ROI was 1:1.93, 1:3.86, 1:7.79, 1:8.04, 1:18.72, and 1:26.90 in 2D, and 1:1.95, 1:3.71, 1:7.10, 1:7.49, 1:15.10, and 1:23.24 in 3D. The differences of percentage were 3.50%, 3.47%, 8.12%, 8.02%, 10.58%, and 11.06% in 2D, the minimum differentiation was 3.47%, and the maximum one was 11.06%. In 3D, the difference of percentage was 3.66%, 4.80%, 8.38%, 23.92%, 23.86%, and 22.69%. Conclusion: The difference of accumulated concentrations is significantly increased following enhancement of radioactivity concentration. The change of radioactivity density in 2D image is affected by less than 3D. For those reasons, when patient is examined as follow up scan with changing the acquisition mode, scan should be conducted considering those things may affect to the quantitative analysis result and take into account these differences at reading.

• Korean Journal of Agricultural Science
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• v.17 no.2
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• pp.115-129
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• 1990

This study was carried out to develop a microcomputer-based data acquisition system and software for analysis of engine vibration. Due to this development of system and software, studies on the vibration of engine was able to conduct efficiently. From the display of CRT, the outputs of test was compared and analysed on a zero-base motoring. The results obtained are summarized as follows : 1. Data acquisition system in microcomputer were designed and programmed and operated accurately. 2. The result of test was easily compared in monitoring of zero-base at color monitor. 3. This system and program developed was able to control the measuring intervals, no. of channels, and no. of data as wated. 4. The type of vibration of engine was type of bi-mode from the FFT and statistical analysis. 5. The maxima of engine vibration were 9.11 G at X-axis. 11.27 G at Y-axis, and 4.9 G at Z axis for full load of net output 6. The maxima of engine vibration unloaded were 4.28 G, 5.59 G, 2.68 G at 2200 rpm.

• Korean Journal of Microbiology
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• v.4 no.2
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• pp.19-21
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• 1966

For the purpose of determining possibility of aphid-transmission of mosaic disease of black locust, cowpea aphid (Aphis medicagnis Koch) and green peach aphid (Myzus persicae Sulzer) were experimented using cowpea as test plant, and both proved to be the vectors. As for transmission threshold period of cowpea aphid to the virus, the acquisition feeding period was five seconds and inoculation feeding period was two minutes. This black locust mosaic virus, therefore, is a nonpersistent virus.

• English Language & Literature Teaching
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• v.11 no.3
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• pp.71-87
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• 2005

The role of interaction in second language (L2) classrooms has been examined from different angles, ranging from early studies of foreigner talk to the studies of the teacher- and task-based talk. However, most of the research on L2 classroom interaction has been based on a traditional psycholinguistic view of language and learning, failing to reconceptualize a broad and holistic understanding of L2 learning. Currently, many researchers have attempted to explore and describe classroom interaction in L2 classrooms from a sociocultural perspective. The purpose of this paper is to discuss Vygotsky's theoretical framework in terms of L2 classroom interaction and research from a sociocultural perspective, by describing three key concepts (zone of proximal development, private speech, and activity theory) in Vygotsky's theoretical framework and relating them to L2 classroom interaction. The results demonstrated the importance of social interaction for second language acquisition with the review of the related research study. It was also suggested that the dynamic and interactive processes of second language learning in the classroom should be valued by L2 researchers as well as L2 teachers. Finally, implications for the concepts for L2 classroom research and pedagogy are presented in the conclusion.

• Journal of Power Electronics
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• v.14 no.3
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• pp.444-457
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• 2014

This paper presents the design and realization of a digital PV simulator with a Push-Pull Forward (PPF) circuit based on the principle of modular hardware and configurable software. A PPF circuit is chosen as the main circuit to restrain the magnetic biasing of the core for a DC-DC converter and to reduce the spike of the turn-off voltage across every switch. Control and I/O interface based on a personal computer (PC) and multifunction data acquisition card, can conveniently achieve the data acquisition and configuration of the control algorithm and interface due to the abundant software resources of computers. In addition, the control program developed in Matlab/Simulink can conveniently construct and adjust both the models and parameters. It can also run in real-time under the external mode of Simulink by loading the modules of the Real-Time Windows Target. The mathematic models of the Push-Pull Forward circuit and the digital PV simulator are established in this paper by the state-space averaging method. The pole-zero cancellation technique is employed and then its controller parameters are systematically designed based on the performance analysis of the root loci of the closed current loop with $k_i$ and $R_L$ as variables. A fuzzy PI controller based on the Takagi-Sugeno fuzzy model is applied to regulate the controller parameters self-adaptively according to the change of $R_L$ and the operating point of the PV simulator to match the controller parameters with $R_L$. The stationary and dynamic performances of the PV simulator are tested by experiments, and the experimental results show that the PV simulator has the merits of a wide effective working range, high steady-state accuracy and good dynamic performances.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.4
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• pp.347-351
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• 2021

Objective: We investigated the impact of vitamin D₃ (VD3) supplementation during mouse preantral follicle culture in vitro and the mRNA expression of 25-hydroxylase (CYP2R1), 1-alpha-hydroxylase (CYP27B1), and vitamin D receptor (VDR) in mouse ovarian follicles at different stages. Methods: Preantral follicles were retrieved from 39 BDF1 mice (7-8 weeks old) and then cultured in vitro for 12 days under VD3 supplementation (0, 25, and 50 pg/mL). Follicular development and the final oocyte acquisition were assessed. Preantral follicles were retrieved from 15 other BDF1 mice (7-8 weeks old) and cultured without VD3 supplementation. Three stages of mouse ovarian follicles were obtained (preantral, antral, and ruptured follicles). Total RNA was extracted from the pooled cells (from 20 follicles at each stage), and then reverse transcriptase-polymerase chain reaction was performed to identify mRNA for CYP2R1, CYP27B1, and VDR. Results: The survival of preantral follicles, rates of antrum formation and ruptured follicles (per initiated follicle) and the number of total or mature oocytes were all comparable among the three groups. Both CYP2R1 and CYP27B1 were expressed in antral and ruptured follicles, but not in preantral follicles. VDR was expressed in all three follicular stages. Conclusion: VD3 supplementation in vitro (25 or 50 pg/mL) did not enhance mouse follicular development or final oocyte acquisition. Follicular stage-specific expression of CYP2R1, CYP27B1, and VDR was observed.

• Journal of Ginseng Research
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• v.23 no.2 s.54
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• pp.115-121
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• 1999

Effects of single and repeated administration of various nootropic candidates were examined on impaired acquisition by single oral administration of 3 g/kg ethanol (EtOH) in step through test. The inhibitory effect of EtOH on acquisition was significantly reduced by single picrotoxin, but not affected by diazepam, acetyl-L-carnitine and apomorphine. Single or repeated red ginseng total saponin and deprenyl, single piracetam, repeated N-methyl-D-glucamine, but not single or repeated protopanaxadiol, protopanaxatriol and centrophenoxine significantly ameliorated the impairment of acquisition by EtOH. On the other hand, the inhibitory effect of repeated red ginseng total saponin but not that of repeated N-methyl-D-Glucamine, was significantly blocked by pretreatment of $\alpha$-methyl-$\rho$-tyrosine, a inhibitor of catecholamine synthesis. Whereas, the inhibitory effect of repeated deprenyl on EtOH amnesia was exaggerated by $\alpha$-methyl-$\rho$-tyrosine. These results suggest that the amelioration processes of drugs on ethanol amnesia involve complex mechanism between the central GABAergic and dopaminergic neuronal activity in memory and learning, although the effects of repeated drugs administration are not yet clear.

• Industry Promotion Research
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• v.2 no.2
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• pp.1-6
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• 2017

SCADA (Supervisory Control and Data Acquisition) System was first introduced to the Seoul Electricity Authority, which manages the transportation part among the three business fields that produce, transport and supply electric power in Korea. Has been using the data link with 1200 bps and 9600 bps in 5 protocols such as HARRIS 6000, BSC, HDLC, L & N and Toshiba by configuring 3 layers of EMS, SCADA and RTU computer equipments in 1: N radial form. This paper presents the OSI standard network packet flow, analyzing DataLink and Network Layer, and presents a KEPCO SCADA network model composed of X.25 high - speed communication network using 3 layers of network. We proposed a future SCADA communication structure that improved the current SCADA communication structure, defined the SCADA DB structure, introduced the concept of the remote SCADA gateway to the SCADA functional structure, applied the standard communication protocol, Multiplexing of surveillance and control in other local facilities and ensuring communication openness.

• The Korea Journal of Herbology
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• v.38 no.5
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• pp.39-47
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• 2023

Objectives : The objective of present study was to investigate the vasorelaxant effects of 20 Korean native plants on isolated rat thoracic aorta precontracted with phenylephrine (PE). Methods : Dried 20 plant materials were extracted 3 times with water, ethanol, or methanol for 3h in the reflux apparatus at 70 ± 5℃. Male SD rats were anesthetized by ether inhalation, and their aorta rings were isolated and placed in 10 ㎖ Krebs Henseleit (KH) buffer. While using an isolated organ-chamber technique, the aorta rings were maintained by bubbling with a gas mixture of 95% O₂-5% CO₂ at 37℃. Changes in isometric tension of aorta rings were recorded via isometric transducers connected to a Powerlab Data Acquisition System. Results : Among the 20 native plants, Chrysanthemum indicum L. flower, Nelumbo nucifera Gaertn. rhizome, Schisandra chinensis (Turcz.) Baill. fruit, Anthriscus sylvestris (L.) Hoffm. root, Corydalis turtschaninovii Besser tuber, Corydalis decumbens (Thunb.) Pers. tuber, and Dolichos lablab L. seed showed significant vasorelaxant effect on the contraction of aorta rings induced by PE. In contrast, Mertensia maritima subsp. asiatica Takeda whole plant, Ajuga decumbens Thunb. whole plant, Trigonotis peduncularis (Trevis.) Benth. ex Baker & S.Moore whole plant, Dioscorea quinquelobate Thunb. rhizome, Allium microdictyon Prokh aerial part, Momordica charantia L. fruit, Carthamus tinctorius L. flower, and Clematis terniflora DC. root constricted more the aorta rings precontracted by PE Conclusion : These results suggest that the possibility as useful herbal resources for the development of functional foods or medicines for hypertension treatment.