• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.274-279
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• 2009

To determine the critical level for optimum maturity of flue-cured tobacco leaves (KF118) at the stalk position from cutter to tips, the reflectance index using ground-based remote sensors and chlorophyll meter were investigated. The sensors estimated were Crop $Circle^{TM}$ (Holland Scientific), Green $Seeker^{TM}$ (Ntech Industries), Spectroradiometer (LICOR, LI-1800), Chlorophyll meter (SPAD502, Minolta), and Field $Scout^{TM}$ Chlorophyll meter (CM-1000, Spectrum). The L, a, b values and greenness for flue-cured leaf were measured and estimated for correlation with sensor's measurement of harvested leaf. On a reflectance curve of 340nm~1100 nm, the reflectance peaks on 550nm and 675 nm for the harvested leaf were lowered as change from light green to darker green. Darker green leaf harvested produced darker flue-cured leaf. The reflectance at 675 nm for flue-cured leaf decreased as greenness increased in the harvested leaf. This result means that the red edge band of 675 nm wavelength is related to the absorbance of chlorophyll for photosynthesis. The greenness of flue-cured leaf showed significantly positive correlation with the entire reflectance indexes for harvested leaf while the L value by colorimeter showed negative correlation with greenness of cured leaf. The critical level for optimum maturity of harvested leaf were less than 22, 135, and 0.43 for SPAD reading, CM-1000 reading, and gNDVI by Crop $Circle^{TM}$, respectively. Consequently, ground-based remote sensing providing a non-destructive real-time assessment of plant greenness could be a useful tool in the selection of optimum maturity of flue-cured tobacco leaves in relation to high quality of flue-cured tobacco.

• The Journal of Art Theory & Practice
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• no.10
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• pp.47-61
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• 2010

What is Art on the street? Is it a series of artworks or activities performed on the street? In other words, does "art on the street" refer to "Street Art" such as street performance, happening, graffiti, or wall-painting, or does it refer to "Street Furniture" which is related to "City Design" or "Environmental Design"? In a formal sense, they all belong to Art on the street. However, in this paper, I would like to use Art on the street in an even broader sense. To me, " the street" is a metaphor of "environment." Thus Art on the street is the art related to environment; it is an environment art. Art on the street attests the expansion of the concept of art and shows a new possibility of contemporary art. It is a promising new concept of art, but we cannot ignore the misapplication of the concept that we can find at the crossroad of Art on the street and "city beautification." Of course, Art on the street can and sometimes needs to beautify the city. However we still need to ask how to contribute to the city beautification with Art on the street and how to validate such a practice. City space is, most of all, a space that people live in. It sounds a cliche, but it is worth repeating to better understand Art on the street. When we consider the city space in terms of its system or organization, we often overlook that it is the space in which people live, and which people create. Art on the street concerns not the city itself, but the space in which people live and make relations for each other. Without taking this into account, Art on the street becomes a mere means to' embellish' the city and falls prey to the logic of capital. In this paper, I critically reviewed the problems such as City Development, Spectacularization, City Environmental Design, Public Interest and City Museum. I intended to emphasize that Art on the street is produced in the cultural space of city, but it also tends to break the mold of the cultural space and seeks a new possibility. Some might argue that my claims are unrealistic because Art on the street is not an idea but a practice. While humbly accepting the objection, I hope my critical suggestions guide a more productive direction to continue our discussions of Art on the street.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.969-978
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• 2016

The purpose of this study is to figure out gifted elementary science students' improvement in performing open inquiry after peer review. In this study, gifted fifth-grade students performed open inquiry and review of each other as peers after the inquiry. Students' inquiries were evaluated and the influences of the feedback from the peer reviews were analyzed in relation to the inquiry performances. As a result of this study, three key points were discovered: First, the evaluation score increased with frequent feedback or long discussions. On the other hand, with less feedback, the evaluation score didn't rise. Second, there were three types of improvement in inquiry related to peer review: No. 1 was improvement after feedback given by themselves. No. 2 was reflection of feedback given to other groups. As a last type, No. 3 was that the students learned from other groups' presentation without any feedback and improved their inquiry. Third, there were five kinds of giving feedback; (1) feedback understanding the inquiry correctly, (2) insufficiency of peer's inquiry without deep thought. (3) on the usefulness of the inquiry, (4) on the scientific and logic validity through critical thinking, and (5) how to develop the inquiry. In these kinds of feedback, the fourth kind of feedback (4) occurred most frequently but the fifth (5) occurred rarely. It means peer review helps students develop their critical thinking ability and teachers should encourage students to give peers feedback of the fifth kind.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.3
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• pp.17-25
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• 2012

Wire bonding process in making semiconductor needs the most precise control and Critical To Quality(CTQ). Thus, it is regarded to be the most essential step in packaging process. In this process, pure gold wire is used to connect the chip and PCB(substrate or lead frame). However, the price of gold has been skyrocketing continuously for a long period of time and is expected to further increase in the near future. This phenomenon situates us in an unfavorable condition amidst the competitive environment. To avoid this situation, many semiconductor material making companies developed new types of wires: Au.Ag wire is one material followed by many others. This study is aimed to optimize the parameter in wire bonding with the use of 6sigma and QFD(Quality Function Deployment). 6sigma process is a good means to not only solve the problem, but to increase productivity. In order to find the key factor, we focused on VOB(Voice of Business) and VOC(Voice of Customer). The main factors from VOB, VOC are called CTQ. However, there were times when these main factors were far from offering us the correct answer, thus making the situation more difficult to handle. This study shows that QFD aids in deciding which of the accurate factors to undertake. Normally QFD is used in designing and developing products. 6sigma process is held more effective when it used with QFD.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.556-562
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• 2012

The critical micelle concentration (CMC) and the counter-ion binding constant (B) for the mixed micellizations of TTAB (tetradecyltrimethylammonium bromide) with other surfactants (DTAB, CTAB, Tween-20, Tween-40, and Tween-80) in aqueous solution of 4-chlorobenzoic acid (0.5 mM) at $25^{\circ}C$ were determined as a function of ${\alpha}_1$ (the overall mole fraction of TTAB) by using the spectrophotometric method and the conductivity method. Various thermodynamic parameters ($X_i$, ${\gamma}_i$, $C_i$, $a_i^M$, ${\beta}$, and ${\Delta}H_{mix}$) were calculated for each mixed surfactant system and compared with the other mixed surfactant systems by means of the equations derived from the nonideal mixed micellar model. The results show that TTAB/DTAB mixed system has a great positive deviation from the ideal mixed micellar model and the other mixed systems have great negative deviations from the ideal mixed model.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.7-15
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• 2018

The friction factors according to the flow regimes in helical coil tubes depend on the coil diameter, the tube diameter, and the coil pitch. In previous studies, correlations for the laminar flow regime in helical coil tubes have been proposed. However, studies on the transition flow regime and the turbulent flow regime are insufficient and further researches are necessary. In this study, characteristics of the friction factors for the laminar, transition and turbulent flow regimes in helical coil tubes were experimentally investigated. The helical coil tubes used in the experiments were made of copper. The curvature ratios of the helical coil tubes, which means the ratio of helical coil diameter to inner diameter of the helical coil tube are 24.5 and 90.9. Experiments were carried out in the range of $529{\leq}Re{\leq}39,406$ to observe the flows from the laminar to the turbulent regime. The friction factors were obtained by measuring the differential pressures according to the flow rates in the helical coil tubes while varying the curvature ratios of the helical coil tubes. Experimental data show that the friction factors for the helical coil tube with 24.5 in the curvature ratio of the helical coil tube were larger than those in the straight tube in all flow regimes. As the curvature ratio of the helical coil tube increases, the friction factor in turbulent flow regime tends to be equal to that of the straight tube. In addition, it was confirmed that the transition flow regimes in the helical coil tubes were much wider than those in the straight tube, also the critical Reynolds numbers were larger than those in the straight tube. The results obtained in this experimental study can be used as basic data for studies on the water hammer phenomenon in helical coil tubes.

• The Journal of Society for e-Business Studies
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• v.15 no.4
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• pp.143-163
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• 2010

The purpose of this study is to investigate the user's perception of security risk and examine its impact on the usage of Knowledge Management Systems(KMS). The findings of this study are three-fold. First, the overall user's perception of security risk is not high. However, there is a considerably big difference in the perception of security risk among users. This finding means that user's perception of a security risk is not based on the actual security effects but one's individual perception. Another finding is that user's perception of a security risk has a negative impact on the usage of KMS through "trust", which is a mediating variable in our study. This finding corresponds with the existing theory that security risk is oneof the critical sources of trust, and trust is a critical factor of user's acceptance of KMS. Finally, the result of this study reveals that activities devoted to security do not decrease the effectiveness and productivity of KMS. Our long-held cognition that security activity hinders the effectiveness and productivity of an information system is not particularly applied to the KMS.

• Journal of The Korean Association For Science Education
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• v.36 no.3
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• pp.457-470
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• 2016

We investigated the conceptual and methodological characteristics of self-study as an innovational way with reflective research methods and explored the possibility of application of self-study in the field of science education by reviewing previous researches done in foreign countries. The results show that Self-study in education means the study of self, self-practice, self-thought, and so on in the teaching and learning context. It is a kind of new research method to pursue the improvement of teaching and learning practice with integrated perspectives on the context of instruction, identities of members, their beliefs and values, innovation agenda for better education, etc. This can be attained by collective and critical reflection in doing research. Most previous articles on the methodology of self-study suggested that the self-study should be more than just daily journals written only by her/him self. To do self-study in the academic way, they requested interaction with critical and cooperative colleagues, multiple but strict qualitative research methods, and participants' efforts for making better practice in instruction. Similar features to the above are found in the previous 14 self-study papers related to science education done in foreign countries. Based on the results, we concluded that self-study could be applied usefully into the field of science education in Korea. This paper could contribute to stimulation in the innovation of science instruction in a more practical way by increasing the attention to self-study and provoking its practice in Korea.

• Journal of the Korean Chemical Society
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• v.53 no.2
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• pp.118-124
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• 2009

The values of critical micelle concentration (CMC) and counter ion binding constants (B) in a micellar state of CPC (1-hexadecylpyridinium chloride) with Brij 35 (polyoxyethylene(23) lauryl ether) in water were determined as a function of ${\alpha}_1$ (the overall mole fraction of CPC) by the use of electric conductivity method. Various thermodynamic parameters ($X_i,\;{\gamma}_i,\;C_i,\;a_{i}^{M},\;\beta,\;and\;{\Delta}H_{mix}$) were calculated and analyzed by means of the equations derived from the non-ideal mixed micellar model. And thermodynamic parameters (${\Delta}{G^o}_m,\;{\Delta}{H^o}_m,\;and\;{\Delta}{S^o}_m$) for the micellization of CPC/Brij 35 mixtures were also calculated from the temperature dependence of the CMC values. The values of ${\Delta}{G^o}_m$ are all negative, but the values of ${\Delta}{S^o}_m$ and ${\Delta}{H^o}_m$ are positive or negative, depending on the measured temperature and ${\alpha}_1$.

• Journal of The Korean Association For Science Education
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• v.30 no.1
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• pp.140-156
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• 2010

This study aimed to investigate how science teachers perceived major features of the 2007 revised science curriculum and implementing them in classes. The 2007 revised science curriculum included critical features such as creativity, open inquiry, science writing, discussion and STS. In terms of necessity, clarity and complexity of those features for curriculum implementation, teacher perceptions were examined. Particularly with regard to open inquiry assigned 6 class periods per semester as one of the critical features of 2007 revised science curriculum, we asked teachers how they would prepare and implement the technique in their teaching. In results of this study, science teachers agreed on the necessity and importance of those major features of the 2007 revised science curriculum, including creativity, open inquiry, science writing, discussion, and STS. However, they were not clear on how those would work in their classrooms and expected various impediments. Open inquiry was specifically perceived as most negative in its implementation with the mention of various complex reasons. Based on findings in this study, we proposed the 'Dual Action Research Model' for curriculum implementation. It tries to explain how curriculum is implemented in classrooms and diminish the gaps between curriculum developers and teacher users by means of leading teachers to understand the curriculum meaningfully and implement their teaching based on this understanding.