• Korean Journal of Materials Research
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• v.4 no.3
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• pp.364-375
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• 1994

The microstructure of medium-carbon non-heat treated steels by air-cooling shows ferritepearlite structure. Compared to the conventional Q/T steels, the strength of these steels containing V, Nb and Ti are similar to Q/T steels. However, their toughness are inferior. In this study, the mechanical properties and microstructures of low-carbon Mo bearing steels produced by direct-quenching process were investigated. Especially, the effect of Mo on the direct-quenched steels was examined. The direct-quenched steels containing Mo were found to have higher strength and toughness. Mo seemed to be effective in producing the fine structure and dense precipitates because of decreasing transformation temperature. The best results were 1211 MPa in UTS and 127.5 J in toughness in the oil quenched 0.15C+O.llV+ 0.035Nb+ 1.81Mo steel. Compared to 0.4% C microalloyed steels, this results showed that UTS increased by 45% and toughness by 2 times.

• Korean Journal of Materials Research
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• v.8 no.2
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• pp.165-172
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• 1998

Epitaxial ultrathin films of $CoSi_2$ and double heteroepitaxial structure of Si/$CoSi_2$/Si(lll) were prepared on Si(111)-$7\times{7}$ substrate by in situ solid-phase epitaxy in a ultrahigh vacuum(LHV). The phase, chemical composition, crystallinity, and the microsructure of the Si/$CoSi_2$/Si(lll) interface were investigated by 2-MeV $^4He^{++}$ ion backscattering spectrometry, X-ray diffraction, and high-resolution transmission electron microscopy. The growth mode of the Co film was the Stransky-Krastanov type with texture when the substrate temperature was room temperature. A-type $CoSi_2$ ultrathin film was grown by deposition of about 50A Co on Si(ll1)-$7\times{7}$ substrate followed by in situ annealing at $700^{\circ}C$ for 10 min. The matching face relationships were $CoSi_2$[110]//Si[110] and $CoSi_2$(002)//Si(002) with no misorientation angle. The A-type $CoSi_2$/Si(lll) interface was abrupt and coherent. The best epi-Si/epi-$CoSi_2$2(A-type)/Si(lll) structure was obtained by deposition of Si film on the CoSii at $500^{\circ}C$ followed by in situ annealing at $700^{\circ}C$ for 10 min in UHV.

• Korean Journal of Materials Research
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• v.5 no.2
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• pp.239-245
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• 1995

Mn-Zn ferrite thin films were deposited on $SiO_2(1000 \AA)/Si(100)$ by ion beam sputtering using a single ion source. A mosaic target consisting of a single crystal(ll0) Mn-Zn ferrite with a Fe metal strip on it was used. As-deposited films without oxygen gas flow have a wiistite structure due to oxygen deficiencies, which originated from the extra metal atoms sputtered from the metal strips during deposition. The as-deposited films with oxygen gas flow, however, have a spinel structure with (111) preferred orientation. The crystallization of thin films was maximized at the ion beam extraction voltage of 2.lkV, at which the deposited films are bombarded appropriately by the energetic secondary ions reflected from the target. As the extraction voltage increased or decreased from the optimum value, the crystallinity of thin films becomes poor owing to a weak and severe bombardment of the secondary ions, respectively. Crystallization due to the bombardment of the secondary ions was also maximized at the beam incidence angle of $55^{\circ}$. The as-deposited ferrite thin films with a spinel structure showed ferrimagnetism and had an in-plane magnetization easy axis.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.791-798
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• 2009

The goal of this study is leading discussion on emotional design focused on product domain and approaching it through a practical way so that it'll be able to help designers in their real design work when they design products in an emotional way. Discussions on emotions are remaining on abstract levels and only focusing on 5 senses even though the importance of emotions are increased. But much more is needed to apply emotions in the product domain because these are not the proper forms for applications and they only cover limited parts of it. Therefore, in this study we proposed the notion of 'Emotionalized Product' and defined it into a practical level. We extracted 5 useful frameworks of 'Emotionalized Product(EP)' as a results; EP Media, EP Procedure, EP Level, EP Character, and EP Value. Then we clarified EP with these frameworks. After that, we extracted 2 frameworks: Domain Structure, and EP Opportunity, to combine EP with a real product. Finally we proposed the EP Design Process consisted of Inductive and Deductive Process based on previous work. It can be shared by designers as a base of designing system, and it also can be helpful to design products more successfully with an emotional approach.

• Korean Journal of Materials Research
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• v.15 no.7
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• pp.439-443
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• 2005

The oxidation behavior and the thermal stability of nanocrystalline Al-25Ti-8Mn intermetallic compound were investigated. $Al_3Ti$ intermetallic compound, which has a potential for high temperature structural material, was fabricated by mechanical alloying(MA) with $8at.\%$ Mn to enhance the thermal stability and ductility. And Al-25Ti-8Mn intermetallic compound was sintered by spark plasma sintering(SPS) at $700^{\circ}C$. After sintering process, cubic $Ll_2$ structure was maintained without phase transformation and the grain size was about 50nm. To investigate the oxidation behavior of the specimens, thermal gravimetric analysis(TGA) was performed at 700, 800, 900, and $1000^{\circ}C$ for 24 h in $O_2$. As the temperature increased from $700^{\circ}C\;to\;900^{\circ}C$ the weight gain of specimens increased. However at $1000^{\circ}C$, unlike the oxidation behavior of $700^{\circ}C\;to\;900^{\circ}C$, the weight gain of specimen decreased drastically and the transition from linear rate region to parabolic rate region occurred rapidly due to the dense $\alpha-Al_2O_3$.

• Journal of The Korean Association For Science Education
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• v.17 no.1
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• pp.1-10
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• 1997

The purpose of this study was to analyze the structural model of causal effects of students' variables on science process skills. Student characteristics investigated in the study included attitude related to the science, logical thinking ability, scientific experiences, cognitive style. Covariance structural modeling procedures were used to test causal inferences about hypothesized relationships. The sample consisted of 319 6th grade students and 321 8th grade students in Seoul City, Korea. Five instruments were used in the study, TSPS(test of science process skills), GALT(group assessment of logical thinking), CEFT(children embedded figures test), questionnaire of attitude related to the science, questionnaire of scientific experience. For statistical analysis, the study adopted the structural equation modeling with LlSREL, a computer statistical program developed by J reskog and S rbom. Major findings of the study are as follows:1) Logical thinking ability has a most strong direct effect on science process skills. 2) The structural coefficient of scientific experience influence on attitude related to the science has the greatest direct one than the others in the covariance structural model. According to the results of this study, it is very importance that various scientific experiences, particularly hands-on activity, should be offer to students to improve science process skills. Also, understanding the relationships of student variable to science process skills will be helpful to decision making on the part of curriculum developers, science teachers and researchers.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.13-18
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• 2002

Effects of divalent cations such as $Mg^{2+}$, $Mn^{2+}$ and $Zn^{2+}$ on the self-splicing inhibition of the T4 phage thymidylate synthase (td) intron by the coenzyme thiamine pyrophosphate have been investigated. The splicing activity increased in proportion to the concentration of $Mg^{2+}$ up to 30 mM. Without $Mg^{2+}$in the splicing reaction the $Zn^{2+}$ ion tested in the range of 0.1-6 mM concentration only produced the splicing activity about 20% that of the normal splicing rate. A majority of the splicing products were I-E2 and E2 but El-E2 ligation product, Cl and Ll were not detected. Similar patterns of splicing products were also observed with $Mn^{2+}$. At 6 mM $Zn^{2+}$the intron RNA was hydrolyzed. $Mn^{2+}$produced a little higher splicing activity than that of $Zn^{2+}$over the range of concentrations used and at 8 mM about 28% splicing activity was observed. In contrast, $Mn^{2+}\;and\;Zn^{2+}$ ions promoted the splicing activity about 35-40% on an average in the presence of 10 mM $Mg^{2+}$. Of all divalent cations tested, $Mg^{2+}$exhibited the maximum activation effect to counteract the splicing inhibition by thiamine pyrophosphate. This appears to be due to the stabilizing effect of td intron ribozyme structure essential for the catalytic function by $Mg^{2+}$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.4
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• pp.9-21
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• 2008

In this paper, we propose a GNSS-based RF receiver, A high precision localization architecture, and a high sensitivity localization architecture in order to solve the satellite navigation system's problem mentioned above. The GNSS-based RF receiver model should have the structure to simultaneously receive both the conventional GPS and navigation information data of future-usable Galileo. As a result, it is constructed as the multi-band which can receive at the same time Ll band (1575.42MHz) of GPS and El band (1575.42MHz), E5A band (1207.1MHz), and E4B band (1176.45MHz) of Galileo This high precision localization architecture proposes a delay lock loop with the structure of Early_early code, Early_late code, Prompt code, Late_early code, and Late_late code other than Early code, Prompt code, and Late code which a previous delay lock loop structure has. As we suggest the delay lock loop structure of 1/4chips spacing, we successfully deal with the synchronization problem with the C/A code derived from inaccuracy of the signal received from the satellite navigation system. The synchronization problem with the C/A code causes an acquisition delay time problem of the vehicle navigation system and leads to performance reduction of the receiver. In addition, as this high sensitivity localization architecture is designed as an asymmetry structure using 20 correlators, maximizes reception amplification factor, and minimizes noise, it improves a reception rate. Satellite navigation system repeatedly transmits the same C/A code 20 times. Consequently, we propose a structure which can use all of the same C/A code. Since this has an adaptive structure and can limit(offer) the number of the correlator according to the nearby environment, it can reduce unnecessary delay time of the system. With the use of this structure, we can lower the acquisition delay time and guarantee the continuity of tracking.

• The Critical Review of Religion and Culture
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• no.32
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• pp.257-287
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• 2017

It seems to be quite an ambitious endeavor to trace back the translation history of Catholic Vulgate Bible from Latin language to Asian languages since 16th century. I try to bring out the translation(translative) procedure of Latin Bible to the Chinese Version, which is eventually come up (and the latter)to the Korean Version. It has been supported and funded by the National Research Foundation of Korea. This task has a three-year plan. For the first step(operation), I examined and searched the European situation of the Vulgate Bible in the Catholic Church, i.e. the ritual use of Vulgate Bible in the Mass and the religious retreat. The liturgical texts, to begin with, were analysed to disclose how the Vulgate Bible was reflected in them. The Lectionary and the Evangeliary were the typical ones. The structure or the formation system of the Lectionaries for Mass was based on the liturgical year cycle. From this point, the Vulgate Bible was rooted in the religious life of European Catholics after the Council of Trent which had proclaimed the Vulgate to be authentic source of the Revelation, therefore, to be respected as the only authoritative Bible. How did the Catholic Church use the Vulgate Bible out of the context and the boundary (sphere) of liturgy? The Meditation guide books for the purpose of instructing the religious retreat was published and (diffused) circulated among the priests, the religious persons and even the laymen. In those books also were included (found) the citation, the interpretation and the commentaries of the Vulgate Bible. The most of the devotees in Europe read the biblical phrases out of the meditation guide books. There are still remained the unsolved problems of how to understand (for understanding) the actual aspect of the Vulgate Bible in the European Catholic Church. All the Biblical verses were translated into French and included in the meditation guide books published in France. What did the Holy See think the French translation of the Vulgate Bible? Unfortunately, there were not found the Vatican Decrees about the European translation of the Vulgate Bible. The relationship between the Vulgate Bible and the Meditation guide (Those) will be much important for the study of Chinese translation of it. The search for the Decrees and the researches on it and the European and the non-European translations of the Vulgate Bible will be a continuous task for me as well as the other researchers on these subjects in the future.

• Journal for History of Mathematics
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• v.24 no.4
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• pp.1-6
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• 2011

We investigate a method to find the least common multiples of numbers in the mathematics book GuIlJib(구일집(九一集), 1724) written by the greatest mathematician Hong Jung Ha(홍정하(洪正夏), 1684~?) in Chosun dynasty and then show his achievement on Number Theory. He first noticed that for the greatest common divisor d and the least common multiple l of two natural numbers a, b, l = $a\frac{b}{d}$ = $b\frac{a}{d}$ and $\frac{a}{d}$, $\frac{b}{d}$ are relatively prime and then obtained that for natural numbers $a_1,\;a_2,{\ldots},a_n$, their greatest common divisor D and least common multiple L, $\frac{ai}{D}$($1{\leq}i{\leq}n$) are relatively prime and there are relatively prime numbers $c_i(1{\leq}i{\leq}n)$ with L = $a_ic_i(1{\leq}i{\leq}n)$. The result is one of the most prominent mathematical results Number Theory in Chosun dynasty. The purpose of this paper is to show a process for Hong Jung Ha to capture and reveal a mathematical structure in the theory.