• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.311-316
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• 2001

This study analyzed the influence of paste fluidity and vibration time for fundamental properties of porous concrete. Results of this study were shown as follows; 1) Even if target void ratio is same, void ratio and compressive strength of porous concrete is different according to w/c, paste flow and vibration time. So, In case of target void ratio, we must consider the influence of w/c, paste flow, and vibration time. 2) Though w/c and vibration time are same, as paste flow increase, all void ratio, continuous void ratio, and compressive strength decrease and difference between upper and lower void ratio increase. 3) Though w/c and paste flow are same, as vibration time increase, all void ratio and continuous void ratio decrease and difference between upper and lower void ratio increase. Also, compressive strength increase by 10 seconds and decease after 10 seconds. 4) As types of superplasticizer is different, all void ratio, continuous void ratio, and compressive strength are different. So, we must give consideration to paste fluidity and vibration time in order that increase of strength of porous concrete and distribution of uniform void.

• Journal of the Korean School Mathematics Society
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• v.3 no.1
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• pp.131-148
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• 2000

Above all, the ability to solve problems must be emphasized as a basic skill of mathematics, but it is neglected when we teach. In this study, learning task means ［same meaning］ ［same form］ ［same technique］, so I tried to extend mathematical scholastic ability of the students as an extensional problem solving that is a basic element of mathematics. The purpose of this study is the investigation of level type learning, using the basic learning elements to extend thinking ability. From the constructed hypothesis as follows and then implement it. I selected basic learning elements from an analyzed textbook and then task learning material was created for each level type learning. The problem solving ability will be extended through the level type learning of the small group, using the level type learning task material. The conclusions this study are as follows. The level type learning in small group learning, using and making level type learning material, having basic learning elements in analysed text are. Basic learning content is understood clearly and deeply, so, fundamentally, it is effective in achieving the problem solving in mathematics. It is an effective method to achieve the meta-cognitive faculty because achieved the expected method of solving problems and resulted in the true learning of content.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.3 s.31
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• pp.295-303
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• 1989

This study is to measure the thermal resistance of 7 types of Parka of different materials with thermal manikin and to compare their effects on physiological responses & subjective wear sensations. Following are the results obtained from the experiments 1) From the thermal manikin experiment, i) As an outer layer, although not significant, water proof fabric was warmer than water proof-vapor permeable fabric. ii) In case of insulating material, down was better for thermal resistance than polyester wadding of the same thickness. Moreover, as the down was thicker, it had more efficiency in thermal resistance. However, the marginal efficiency of thickness was found to be decreasing. 2) From the male-subject experiments, i) Chest temperature, mean skin temperature & microclimate temperature showed the same results on thermal resistance as those of the thermal manikin experiment. ii) Only during rest periods, there was a significant difference among 5 insulating materials in the sense of microclimate humidity. The almost same conclusion was obtained from the above experiments. Even the outer layer did not significantly affect thermal resistance & subjective wear sensation, insulating materials had a significant influence upon them. But in case of 3.5 cm down, it gave less comfortable than that of the thinner. Therefore the optional one for the best comfort & thermal resistance among 7 combinatins is the outer layer of water proff-vapor permeable & insulating material of 2.1 cm down.

• Journal of Korean Library and Information Science Society
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• v.30 no.4
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• pp.255-278
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• 1999

The Korean oldbooks that represent the spiritual product of the ancestors in the form of physical shape are absolute need for retrieval and new evaluation through research and discovery. To earn Korean oldbooks that have these values, catalogue of Korean oldbooks and annotation book were used as secondery materials. But since there haven't been publications of Korean oldbook catalogue that can be used as Korean oldbook search engine, Korean oldbooks that has same title was valued differently by the different authors and defined differently according to bibliographic study. And there even has been a case when, even though there is same edition it was consider the only one. Therefor it can cause a lot of mistakes when you can't over look totally. So you can expert better results in structuring DB with computer then publicized catalogue of Korean oldbooks. But at this present time, since all of the DB that have been structured are not unified as one system and operated separately in their organizations, there has been a problem like creating different bibliographic information for same Korean oldbooks. In this study, as one of the solution to the problems of searching Korean oldbooks, we are making a plan to develop the unified retrieval system of Korean oldbooks using hypertext system. And with these finding, we are suggesting the further way of developing retrieval system of Korean oldbooks.

• Journal of Mechanical Science and Technology
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• v.19 no.4
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• pp.1036-1043
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• 2005

Concentric annular heat pipes (CAHP) were fabricated and tested to investigate their thermal characteristics. The CAHPs were 25.4 mm in outer diameter and 200 mm in length. The inner surface of the heat pipes was covered with screen mesh wicks and they were connected by four bridge wicks to provide liquid return path. Three different heat pipes were fabricated to observe the effect of change in diameter ratios between 2.31 and 4.23 while using the same outer tube dimensions. The major concern of this study was the transient response as well as isothermal characteristics of the heat pipe outer surface, considering the application as uniform heating device. A better performance was achieved as the diameter ratio increased. For the thermal load of 180 W, the maximum temperature difference on the outer surface in the axial direction of CAHP was $2.3^{\circ}C$ while that of the copper block of the same outer dimension was $5.9^{\circ}C.$ The minimum thermal resistance of the CAHP was measured to be $0.004^{\circ}C/W.$ In regard to the transient response during start-up, the heat pipe showed almost no time lag to the heat source, while the copper block of the same outer dimensions exhibited about 25 min time lag.

• Journal of Digital Contents Society
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• v.5 no.2
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• pp.143-150
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• 2004

In this paper, we propose and analyze a new scheme which uses the same scramble codes to each group after symbol grouping to reduce the PAPR (peak-to-avenge power ratio) problem in OFDM system. The conventional SLM scheme randomizes OFDM symbols entered into IFFT block by several scramble codes and then transmits the lowest one among PAPRs. Therefore, the SLM scheme can reduce the additional information as many as the number of grouped OFDM symbols by using same scramble codes after M grouping of sub-carriers. It can also improve PAPR performance more than conventional SLM scheme when we use scramble codes as same as those numbers of SLM scheme.

• Journal of Ginseng Research
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• v.6 no.1
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• pp.17-24
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• 1982

This studies were conducted to investigate the changes of saponin pattern, pH and organic acid contents of malt wort added ginseng components during alcoholic fermentation by Sacch. uvarum. The results are as follows. Saponin patterns of fermented wort were same as that of the non- fermented wort, but the weight of former was decreased comparing to that of the latter. pH value of fermented wort contained 0.1∼0.5% of ginseng extract were almost same as that of control(PH 4.23). Lactate, pyruvate, succinate and fumarate, pyroglutarate and citrate contents of the fermented wort were increased by the addition of ginseng extract and pyruvate content, particularly, was increased from 28.4 to 214mg/100 ml while that of control was 33.2mg/100m1. Citrate content of fermented wort contained ginseng saponin was almost same as control (37. 5mg/100m1) . But pyruvate content was tower 4-8.6mg/100m1 than that of control(33.2mg/100m1) .

• Food Science and Biotechnology
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• v.18 no.1
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• pp.66-72
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• 2009

An aqueous ribose-cysteine model system (initial pH 5.6) was conventionally heated to the same browning at varying temperatures ($120-180^{\circ}C$), supercritical carbon dioxide (SC-$CO_2$, 20 MPa) was also applied on the same matrices for same periods at each temperature and about 20% reduction of the absorbance at 420 nm was observed as compared with sole thermal treatment. The headspace volatiles from Maillard reaction mixtures were analyzed by solid-phase microextraction (SPME) in combination with gas chromatography and mass spectrometry (GC-MS), and predominated with sulfur containing compounds, such as thienothiophenes, polysulfur alicyclics, thiols, and disulfides. Reaction temperature exhibited complex effects on volatiles formation and those effects became further complicated by the SC-$CO_2$ treatment. The formation of noncarbonyl polysulfur heterocyclic compounds and thienothiophenes was generally favored at high temperatures. Most volatiles were inhibited in SC-$CO_2$ as compared with thermal treatment alone, however, the well-known meaty aromatic compounds, such as thiols and disulfides, were obviously enhanced.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.4 s.163
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• pp.519-530
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• 2007

This study is an exploratory research on the brand architecture of Korean apparel enterprises and the differentiation strategy among in-house competing brands. For data analysis, secondary data was used. 20 apparel enterprises were used as the subjects. The results are as following. First, as a result of brand architecture composition, apparel enterprises used the strategy that initially paved the way launching several brands in a specific item category and after that diversified to other categories. Most enterprises used the multi-brand strategy operating plural brands in a same zoning. The terms for launching succeeding brands were about $1{\sim}5$ years. Second, as a result of analysing the cases which several brands competes within a same zoning, all the posterior brands had some differences from the prior ones. The most frequent differentiation factor was price. Concept, target age, and distribution channel followed. The order of the factors was somewhat different among the item categories. The differentiation strategy among in-house competing brands meant that the enterprises manage plural brands in a same zoning for the growth of whole market share instead of the direct competition among in-house brands. The results of this study can suggest a growth direction to the enterprises planning to launch new brands.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.4
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• pp.1054-1058
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• 2003

In order to evaluate the direct effect of estrogenic compounds in oriental herbal medicines, the estrogenic activity was measured using an in vitro detection system. For this system, human breast cancer cell line MCF7 was transfected using an estrogen responsive CAT reporter plasmid. Estrogenic activities of Platycodi radix, Astragali radix and Glycyrrhizae radix were evaluated using this system. Estrogenic activity of a 500 ㎍/ml ethanol extract of Platycodi radix was as same as that of a 10/sup -8/ M standard solution (17β-estradiol) and activity of a 50 ㎍/ml ethanol extract was between those of a 10/sup -8/ M and a 10/sup -9/ M standard solutions. In addition, estrogenic activity of a 50 ㎍/ml ethanol extract of Platycodi radix was as same as that of a 10/sup -10/ M standard solution. The same activity patterns were observed in the system which was treated by Astragali radix or Glycyrrhizae radix extracts. The most effective activity was observed in a system which was treated by Platycodi radix extract, but the least activity was observed by Glycyrrhizae radix extract. In this result, it was confirmed that Platycodi radix, Astragali radix and Glycyrrhizae radix extracts possess estrogenic compounds.