• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.302-306
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• 2016

There are various methods to evaluate tree vigor. Cambial electrical resistance represents tree vigor using the method of electrophysiological diagnosis. This study investigated the vigor of several tree species using Shigometer, and compared the differences among the species. The factors, such as foliation, trunk orientation and bark temperature, which affect electrical resistance were also investigated. The needle penetration into cambium was controlled to keep the depth consistent in order to minimize measurement error. Each of three trees were selected from Zelkova serrata, Ginkgo biloba, Metasequoia glyptostroboides, Pinus koraiensis, and Liriodendron tulipifera. The electrical resistances were measured at 60 and 120 cm height of the stem in 4 directions from March until May 2011. The soil conditions in surrounding areas and tree stress responses were also measured. The results were analyzed for the relationship between electrical resistance and the affecting factors. The electrical resistance showed a relatively higher level before foliation until mid-March. The values started to decline from April and recorded a minimal level on May 11. The changes of soil moisture, soil electric conductivity, and tree stress responses during the measurement period showed a similar trend to that of electrical resistance. The Pinus koraiensis, an evergreen conifer, showed few changes on the electrical resistance values during the measurement period. Zelkova serrata, Ginkgo biloba, and Metasequoia glyptostroboides showed the highest bark temperatures and lowest electrical resistances at their south-facing stem. Shigometer can provide measures simple to assess tree vigor in the fields, and to the management of trees.

• Journal of Technology Innovation
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• v.24 no.3
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• pp.107-137
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• 2016

By analyzing a nationwide survey on Korean publics, this study examines the social determinants of public support for three types of scientific research-basic research aimed at pure knowledge, applied research toward industrial application, and research for social problem-solving which aims to enhance ordinary citizens' quality of life. The present study finds the differential effects of social- and political value orientations on the level of public support for respective types of research. As ones have more progressive in their subjective political orientations, they are more likely to support research for social problem-solving than other types of research, while conservatives tend to support basic research and those with neo-liberal ideology tend to support applied research. The Korean public also tends to perceive research for social problem-solving as a counter to basic research while it has been developed against the conventional emphasis on applied research in Korea. Also, the level of support for research for social problem-solving increases with the higher level of trust in scientific authority and expertise, while it has been developed against expertism and included public engagement in science as an important element. Finally, those who have lower income tend to support for research for social problem-solving than other types of research. The implications of these findings are discussed.

• Journal of the Korean Society of Earth Science Education
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• v.11 no.2
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• pp.125-144
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• 2018

The purpose of this study is to analyze the astronomical thinking level of elementary, middle, and high school students using ordered multiple choice items. For this purpose, we constructed a questionnaire comprising three items about spatial thinking and system thinking. This survey was conducted and applied to 1,066 students in the 5th grade, 8th grade, and 11th grade in 12 schools located in Gangwon Province. The collected student response data were analyzed by applying inferential statistics of classical test theory and Rasch model. The results of the analysis were as follows; First, in the level of spatial thinking, students were able to grasp the spatial location and orientation of the celestial body, but were not able to convert the celestial motion of two-dimensional plane into three-dimensional plane, and it was revealed that there is no statistically significant difference in the spatial thinking of students among grade levels. Second, in the level of system thinking, students were able to identify the components and relationship between components of the celestial motion system, but could not identify the patterns of the system, and it was revealed that there was statistically significant difference among the system thinking of students in different grade levels, unlike in spatial thinking. Third, the astronomical thinking expressed in certain context (content) was very similar regardless of grade level, Through this, we could confirm the context-dependency or content-dependency of the astronomical thinking of students. It is expected that the results of this study can be used as basic data for exploring ways to enhance astronomical thinking level in school science classes.

• The Journal of Engineering Geology
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• v.9 no.3
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• pp.187-206
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• 1999

A computer program to numerically predict the permeability tensor of fractured rocks is developed using information on discontinuities which Borehole Televiewer and Borehole Image Processing System (BIPS) provide. It uses orientation and thickness of a large number of discontinuities as input data, and calculates relative values of the 9 elements consisting of the permeability tensor by the formulation based on the EPM model, which regards a fractured rock as a homogeneous, anisotropic porous medium. In order to assess feasibility of the program on field sites, the numerically calculated tensor was obtained using BIPS logs and compared to the results of pumping test conducted in the boreholes of the study area. The degree of horizontal anisotropy and the direction of maximum horizontal permeability are 2.8 and $N77^{\circ}CE$, respectively, determined from the pumping test data, while 3.0 and $N63^{\circ}CE$ from the numerical analysis by the developed program. Disagreement between two analyses, especially for the principal direction of anisotropy, seems to be caused by problems in analyzing the pumping test data, in applicability of the EPM model and the cubic law, and in simplified relationship between the crack size and aperture. Aside from these problems, consideration of hydraulic parameters characterizing roughness of cracks and infilling materials seems to be required to improve feasibility of the proposed program. Three-dimensional assessment of its feasibility on field sites can be accomplished by conducting a series of cross-hole packer tests consisting of an injecting well and a monitoring well at close distance.

• 전기의세계
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• v.28 no.4
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• pp.53-63
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• 1979

Interface recombination velocity in $Al_{x}$G $a_{1-x}$ As-GaAs and $Al_{0.85}$, G $a_{0.15}$ As-GaA $s_{1-y}$S $b_{y}$ heterojunction systems is studied as a function of lattice mismatch. The results are applied to the design of highly efficient III-V heterojunction solar cells. A horizontal liquid-phase epitaxial growth system was used to prepare p-p-p and p-p-n $Al_{x}$G $a_{1-x}$ As-GaA $s_{1-y}$S $b_{y}$-A $l_{x}$G $a_{1-x}$ As double heterojunction test samples with specified values of x and y. Samples were grown at each composition, with different GaAs and GaAs Sb layer thicknesses. A method was developed to obtain the lattice mismatch and lattice constants in mixed single crystals grown on (100) and (111)B oriented GaAs substrates. In the AlGaAs system, elastic lattice deformation with effective Poisson ratios .mu.$_{eff}$ (100=0.312 and .mu.$_{eff}$ (111B) =0.190 was observed. The lattice constant $a_{0}$ (A $l_{x}$G $a_{1-x}$ As)=5.6532+0.0084x.angs. was obtained at 300K which is in good Agreement with Vegard's law. In the GaAsSb system, although elastic lattice deformation was observed in (111) B-oriented crystals, misfit dislocations reduced the Poisson ratio to zero in (100)-oriented samples. When $a_{0}$ (GaSb)=6.0959 .angs. was assumed at 300K, both (100) and (111)B oriented GaAsSb layers deviated only slightly from Vegard's law. Both (100) and (111)B zero-mismatch $Al_{0.85}$ G $a_{0.15}$As-GaA $s_{1-y}$S $b_{y}$ layers were grown from melts with a weight ratio of $W_{sb}$ / $W_{Ga}$ =0.13 and a growth temperature of 840 to 820 .deg.C. The corresponding Sb compositions were y=0.015 and 0.024 on (100) and (111)B orientations, respectively. This occurs because of a fortuitous in the Sb distribution coefficient with orientation. Interface recombination velocity was estimated from the dependence of the effective minority carrier lifetime on double-heterojunction spacing, using either optical phase-shift or electroluminescence timedecay techniques. The recombination velocity at a (100) interface was reduced from (2 to 3)*10$^{4}$ for y=0 to (6 to 7)*10$^{3}$ cm/sec for lattice-matched $Al_{0.85}$G $a_{0.15}$As-GaA $s_{0.985}$S $b_{0.015}$ Although this reduction is slightly less than that expected from the exponential relationship between interface recombination velocity and lattice mismatch as found in the AlGaAs-GaAs system, solar cells constructed from such a combination of materials should have an excellent spectral response to photons with energies over the full range from 1.4 to 2.6 eV. Similar measurements on a (111) B oriented lattice-matched heterojunction produced some-what larger interface recombination velocities.ities.ities.s.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.65-77
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• 2013

Recent economic slump is making the construction industry's overall construction business environment worse. Contractors which are under the legal management and/or walk out are to the brink of 25 companies according to the Construction association of Korea released in 2011. It means that existing construction companies are required to transform the fundamental ideology of existing operation framework, and besides, existing companies should be transformed to service industry in order to proceed further into the developing future industries. In this study, it will be chosen the internal marketing related factor like 'Satisfying employees, internal customer, are the first thing to do in order to satisfy external customer.' which is about existing service industry field before its implementation in construction companies. In addition, appropriateness test will be performed including both interactions between each of the factors affect mutually and looking into any management improvement effects on contractors. And also, this proposal is suggested by approaching with internal marketing strategy which is both paradigm shift for customers by construction company members and another internal communication way as a means of overcoming the crisis of overall construction industry under currently happening.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.9
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• pp.76-84
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• 1999

EZW proposed by Shapiro is based on a zerotree constructed in a way that a parent coefficient in a subband is related to four child coefficients in the next finer subband of similar orientation. This fixed treeing based on 1-to-4 parent-child is suitable to exploti hierachical correlations among subbands but not to exploit spatial correlations within a subband. A new treeing by Joo, et al. is suggested to simulatneously exploit those two correlatins by extending parent-child relationship in a flexible way. The flexible treeing leads to increasing the number of symbols and lowering entorpy comparing to the fixed treeing, and therefore a better compression can be resulted. In this paper, we suggest two techniques to suppress the increasing of symbols. First, a probing bit is generated to avoid redundant scan for insignivicant coefficients. Second, since all subbands do not always require the same kind of symbol-set, produced symbols are re-symbolized into binary codes according to a pre-defined procedure. Owing to those techniques, all symbols are generated as binary codes. The binary symbols can be entropy-coded by an adaptive arithmetic coding. Moerover, the binary symbol stream can give comparatively good performances without help of additional entropy coding. Our proposed coding scheme is suggested in two modes: binary coding mode and arithmetic coding mode. We evaluate the effectivenessof our modifications by comparing with the original EZW.

• Korean Journal of Materials Research
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• v.11 no.2
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• pp.88-93
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• 2001

The thermal behavior and the crystallographic characteristics of an epitaxial $C49-TiSi_2$ island formed in a Si (001) substrate by $N_2$, treatment were investigated by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). It was found from the analyzed results that the epitaxial $C49-TiSi_2$ was thermally stable even at high temperature of $1000^{\circ}C$ therefore did not transform into the C54-stable phase and did not deform morphologically. HRTEM results clearly showed that the epitaxial $TiSi_2$ phase and Si have the orientation relationship of (060)[001]$TiSi_2$//(002)[110]Si, and the lattice strain energy at the interface was mostly relaxed by the formation of misfit dislocations. Furthermore, the mechanism on the formation of the epitaxial $_C49-TiSi2$ in Si and stacking faults lying on the (020) plane of the C49 Phase were discussed through the analysis of the HRTEM image and the atomic modeling.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.3
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• pp.180-188
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• 1999

The dynamic elastic properties of metal matrix composites were investigated by resonant ultrasound spectroscopy(RUS). The composites used in this study consisted of 2124 aluminum alloy reinforced with different concentrations of SiC particles. RUS can determine the nine independent elastic stiffness($C_{ij}$) for the orthorhombic symmetry on a small specimen simultaneously. The elastic constants were determined as a function of the volume fraction. A concept of effective aspect ratio. which combine the aspect ratio and the orientation of reinforcement. was used to calculate the initial moduli from Mori-Tanaka theory for the input of RUS minimization code. Young's moduli can be obtained from the measured stiffnesses. The results show that the elastic stiffness increases with increment of the particle content. The behavior of elastic stiffness indicates that the particle redistribution induced by the extrusion process enlarges the transversely isotropic symmetry as the fraction of reinforced particles increase. This relationship could be used for determination of the volume fractions of reinforcement as a potential tool of nondestructive material characterization.

• Journal of Distribution Research
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• v.13 no.4
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• pp.71-95
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• 2008

Transaction between industrial suppliers and their buyers in business markets increasingly take place in the form of long-tenn business relationships. These relationships are governed through formal or informal agreements. Dynamic business markets are also forcing B2B marketers to create flexibility in their firms. However, buyers are bound in their rationality and find it impossible to contemplate all possible future contingencies. The more formal and detailed the contracts they conclude, the likelier it becomes that at least one buyer is going to perceive a need to adjust the initial agreement as environmental events unfold. In this case, the actor relies upon industrial supplier's competence. Our study purpose is to examine the consequences of supplier's competence on the industrial customer-supplier long-tenn relationship. Antecedent variables of supplier competence include R&D, flexibility, brand asset, market sensing, and customer support service. We presented a comprehensive constructive model consisting of components of supplier's competence and the antecedent factors. Research hypotheses were developed and data were gathered from respondents who work in the cosmetics industry. The results discussed here represent a first step towards a better understanding of the role of supplier competence in the B-to-B cosmetics industry. Managerial implications and the limitations of this research were also discussed.